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  • Current Version:
    Last Edited:
    August 30, 2008

    Search found 3003 instances of

    #ProjectCntryMain PageDescriptionPartsTubesTypeSubtype
    1The Minicaster AM Transmitter  US  Phils Old Radios Now here is a construction approach that anyone can follow. 131A7AM Ham Transmitter1 - 5 Watts
    2Telefunken Daempet Gnistgab  DK  OZ6GH “Gnistgab” is apparently Danish for “spark-gap”. There are about half a dozen Very early spark-gap transmitters shown here in schematic and pictures.  [In Danish. English here] 6[-]AM Ham Transmitter1 - 5 Watts
    3Marconi rotary “gnistgab”  DK  OZ6GH “Gnistgab” is apparently Danish for “spark-gap”. Two approaches from turn of the century are shown here.  [In Danish. English here] 4[-]AM Ham Transmitter1 - 5 Watts
    4Transmitters At Technological Dead-End  DK  OZ6GH Shown are: (a) Marconi wave-train spark-gap, (b) Tesla's 1899 Discharger (AM!), (c) Fessenden 1900 reed-discharge approach, (d) Morietti's transmitter 6[-]AM Ham Transmitter1 - 5 Watts
    57ZM Transmitter  DK  OZ6GH From 1923; a one-valve transmitter with minimal parts. Looks like this could do primitive AM 9[Triode]AM Ham Transmitter1 - 5 Watts
    6Wireless Telephone  DK  OZ6GH At six parts total, I suppose this is as simple as AM gets. 6[Triode]AM Ham Transmitter1 - 5 Watts
    7AM Modulator  US  T Williams Schematic Only 2012AU7, 6BA6 (2)AM Ham Transmitter1 - 5 Watts
    86AQ5 AM Transmitter  US  T Williams Schematic Only 126AQ5AM Ham Transmitter1 - 5 Watts
    9AM Transmitter Using Horizontal Deflection Tubes  BR  Teoria In Portugese; from Brazilian manual apparently.  [In Portugese. English here] 456CD6, 12AU7, 6AQ5, 6CU6 (2)AM Ham Transmitter1 - 5 Watts
    10515 Transmitter  US  FRN's Workshop Notice the lack of isolation transformer. Don't electrocute yourself. 1912AV6, 50C5 (2)AM Ham Transmitter1 Watt
    11Modulador PDM de LU8EHA  ES  GACW No schematic. But interesting  [In Spanish. English here] 12[-]AM Ham Transmitter1 Watt
    12Emisor Radiotelefonico (Phone transmitter)  ES  LU2DCC Short article. For a photo; click the link at the bottom of the page and slect Foto for this project.  [In Spanish. English here] 146F6GAM Ham Transmitter1 Watt
    13Attempt 79: AM Transmitterna  Radiomann Author modifies a Radiomann to be an AM Transmitter. ECC82 is a 12AU7  [In German. English here] 8ECC82AM Ham Transmitter1 Watt
    14Tube AM Transmitterna  Radiomann The Radiomann people point out that their receiver can become a transmitter to the residential area" by increasing the feedback enough.  [In German. English here] 8EF98AM Ham Transmitter1 Watt
    15AM Modulator  DE  Radio Museum Not sure if I'm understanding this right.  [In German. English here] 42ECC82, ECH84AM Ham Transmitter1 Watt
    16AM Transmitter  IT  Le Radio de Sophie Seems simple enough.  [In Italian. English here] 156SN7, 6SK7AM Ham Transmitter1 Watt
    17Adding AM to the DX-20 CW  US  AMFone A general strategy onb how to do this with CW transmitters would be a good thing to have. 96SL7AM Ham Transmitter1 Watt
    18Variable Crystal Oscillator  BR  813 Homepage From Electronica Popular magazine; 1976  [In Portugese. English here] 206AU6, 12BY7AM Ham Transmitter1 Watt
    19Norm Leal's 6888 AM Transmitter  US  Antique Radios Uses a component oscillator. Link to schematic at bottom of page. 136888AM Ham Transmitter1-5 Watts
    20Crystal-Controlled Transmitter with EL84  NL  RadioRob 007 'Dit schema is EXPERIMETEEL'. Schematic Only.  [In Dutch. English here] 15EL84AM Ham Transmitter1-5 Watts
    21N1NKM's Homebrew AM TX  US  My Morninglight BOB = Bucket 'O Bolts". Actually; true homebrew is when you design around what you have. 466AC7(2), 12BY7, 6146(2)AM Ham Transmitter10 - 100 Watts
    2210 Meter Mobile AM Transmitter  US  K3HLN He bought a car because it already had antenna holes drilled in it. 445763, 6SN7, 12AU7, 2E26AM Ham Transmitter10 Watts
    23Een Kleine AM Zender  NL  Radio Morningstar Scroll down half way and look at the homebrew components (for example, the IF transformers using ferrite rod)  [In Dutch. English here] 606AU6(2),ECC83,EL91,EL84,807AM Ham Transmitter10 Watts
    24Um Transmissor Economico  BR  813 Homepage From Antenna (Radio Para Todos") Magazine; Sept. 1949.  [In Portugese. English here] 3912A5, 25L6(4)AM Ham Transmitter10 Watts
    25100 Watt AM Modulator  ES  LU2DCC Schematic only. For a photo; click the link at the bottom of the page and slect Foto for this project.  [In Spanish. English here] 286AU6, 5600, EL36 (2)AM Ham Transmitter100 Watts
    26Transmisor con Modulación  ES  LU8EHA The photos are at  [In Spanish. English here] 506DQ6B (2), 807 (2)AM Ham Transmitter100 Watts
    2715 Watt Kortegolfzender  NL  RadioRob 007 48 meter transmitter. Schematic only.  [In Dutch. English here] 23EL84 (2)AM Ham Transmitter15 Watts
    28The Little Rig  US  AMFone AM Transmitter made from parts found at the dump. 526AK5, 6CX8, 6146, 12AX7, 6EW7AM Ham Transmitter20 Watts
    29200 Watt AM Transmitter  NL  Radio Morningstar Schematic Only.  [In Dutch. English here] 35EL519 (2), 12AX7, EL84AM Ham Transmitter200 Watts
    30Transmisor de 4x4 6DQ6B  ES  LU1DCL Not sure I follow all of this; but it looks like a lot of work.  [In Spanish. English here] 506DQ6 (4)AM Ham Transmitter300 Watts
    31A Home-made Agent Radio  US  Spy Radio Uses the broadcast band so that the receiver can be non-noticeable. 376AG7,2E26,5718,6247AM Ham Transmitter5 - 10 Watts
    325-Watt AM Transmitter Projectna  Electronics Info Schematic only. 416AQ5 (2), 6KE8a (2)AM Ham Transmitter5 Watt
    3310 Watt AM Transmitter  US  FRN's Workshop Schematic only. 246AQ5, 6BQ5AM Ham Transmitter5 Watts
    34K1ETN 5-Watt AM Transmitter  US  FRN's Workshop Don't I already have this somewhere? 336AQ5 (4)AM Ham Transmitter5 Watts
    35Screen modulated AM transmitter  US  FRN's Workshop Schematic only; but it has a lot of commentary on it. 526AG7, 6DQ6, 12AX7, 6SN7AM Ham Transmitter5 Watts
    36BOB Jr (Bucket o Bolts) QRP AM Transmitter  US  My Morninglight Based on a 6BQ5. From N1NKM. 276BJ6, 6AQ5, 6BQ5AM Ham Transmitter5 Watts
    37SBE FM With AM Transmitter  US  AMFone Apparently this mode was/is illegal. I'm not sure of the status. 136DQ6AM Ham Transmitter5 Watts
    3850 Watt MG Zender Met EL84 en 807  NL  Radio Morningstar Very readable schematic, but the Dutch text . . .  [In Dutch. English here] 33EL84,807AM Ham Transmitter50 Watt
    3950 Watt One-tube Transmitter  US  N. Wilson Second project down on the page. Basically a Hartley oscillator. 6211AM Ham Transmitter50 Watts
    40Two 813's Modulating Two 813's RF Deck  US  AM Window 500 Watts out of the Transmitter 38813 (4)AM Ham Transmitter500 Watts
    416 Meter AM Transmitter  JP  JH2CLV Where to they get these line drawings?  [In Japanese. English here] 173A5AM Ham Transmitter6 Meters
    42Homebrew 6 meter Transmitter  US  Boatanchors No schematic; but the schematic is identified as from the late-50's - early 60's ARRL Handbook 3512AX7,6U8,5881(2),6146AM Ham Transmitter6 Meters
    43Vintage Homebrew on 5 Megs  UK  Vmars Manuals (PDF File) Back when 5 Megs meant something. The parts count is a guess, as I can't seem to find a schematic 606BW6,EF80,KT66(2),807(2)AM Ham Transmitter65 Watts
    44Transmissor TRZ100 - PY2WYZ  BR  813 Homepage AM Transmitter for 80 and 40 meters  [In Portugese. English here] 4412AX7, 6CG7, 12BY7, 6146AM Ham Transmitter70 Watts
    45Home Broadcast Transmitter  US  SMECC Transformerless (count of the filaments: 50-50-12) 1512AV6, 50C5(2)AM Ham TransmitterBCB
    46A 'Part 15' Broadcast Band Transmitter  US  Antique Wireless Nice breadboard layout. 246AK5, 6BE6AM Ham TransmitterBroadcast Band
    47Retro-Cakepan transmitter  US  AM Window Uses 3 6AQ5's. Nice looking. 160/80 meters AM. 356AQ5 (3)AM Ham TransmitterHF, 5-10 Watts
    48Muntz AM Transmitter  DK  Fred Nachbaur Uses a pentagrid converter. 136BE6AM Ham TransmitterHF: 1-5 Watts
    49Mid-Quality AM Transmitter  DK  Fred Nachbaur From Fred Nachbaur 236AU6, 6BE6AM Ham TransmitterHF: 1-5 Watts
    50Gypsy Tunable LP AM Transmitter  DK  Fred Nachbaur Uses a pentagrid converter. 3012AU6(2), 12BE6AM Ham TransmitterHF: 1-5 Watts
    51High Quality AM Transmitter  DK  Fred Nachbaur Says he gets 10 milliwatts output to ferrite core antenna. 3512AT7(2),12BE6, 12AU6AM Ham TransmitterHF: 1-5 Watts
    52AM Tube Micro Transmitter  US  Old Radios Lot of theoretical; heavy discussion with this one. 226AV6, 6CS6AM Ham TransmitterHF: 1-5 Watts
    53Siemans Funksend 25a  DE  Seefunk 180M to 80M. Immediate postwar German rig. Translated from the German.  [In German. English here] 30C3e specAM Ham TransmitterHF: 10+ Watts
    54Klaas Robers' 10 watt; 29 MHz all tube NBTV transmitter  UK  NBTV Surprised to see it done at all. 50ECC81(2),EL83,EL84,AM Ham TransmitterNBTV
    55Iron Pyrites Negative Resistance Oscillator  US  Spark, Bang, Buzz Lends new meaning to the term rock-bound transmitter" 5[-]AM Ham TransmitterNon-Traditional
    56Negative Resistance Oscillator with Homemade Tunnel Diode  US  Spark, Bang, Buzz Again; is there a way to make a ham band-legal version of this? 5[-]AM Ham TransmitterNon-Traditional
    57Negative Resistance AM Broadcast band Oscillator  US  Spark, Bang, Buzz Construction technique is Alligator Clip City" 5[-]AM Ham TransmitterNon-Traditional
    58Funken-Induktor nach Marconi  DE  Jogis Roehrenbude In German. Marconi Radio Inductor (Spark Gap Transmitter).  [In German. English here] 3[-]AM Ham TransmitterSpark Gap
    59Lil 7 AM Transmitter72  US  Phils Old Radios Simple tube-based transmitter. (Made for broadcast band; conversion to 80/40 to come) 15117L7AM Ham TransmitterX
    602-tube AM transmitter  US  ElectronixAndMore You wonder if that little thing really works. 146J5, 6AS7AM Ham TransmitterX
    61Carter Modulation AM Transmitter  IT  Research Triangle Author doesn't know if this works. I expect I'll give it a try soon. What is Carter Modulation" anyways?  [In Italian. English here] 1812AT7, SweepAM Ham TransmitterX
    62Home AM Transmitter  US  Glowbugs From Popular Electronics 151U4,1R5AM Ham TransmitterX
    63A Tube-type Class-A DC-Coupled Plate Modulator  US  OPCOM's For Low Power AM Transmitters". I guess I would put this is the class of "design overkill"; but the Hi-Fi guys will go to great lengths for perfection. 406L6,6SH7,6SL7,6AG7,807(2)AM Ham TransmitterX
    64N1NKM's Homebrew AM TX  US  My Morninglight Has a companion receiver. 346CA7(2),6146AM Ham TransmitterX
    65Transmisor Personal de AM  ES  Seccion de Elec In Spanish.  [In Spanish. English here] 136AV^, 6AQ6AM Ham TransmitterX
    66Homebrew 813 AM Transmitter  US  WB4GWA See the extra pages. Not sure if I got it all in. 396SL7,6H6,6J5,6SN7,813(2)AM Ham TransmitterX
    67AM Transmitterna  J Candela AM Homebrew Cathode Modulated Transmitter by Bob Stout 3512AU7,6LF6(2),6AG7,807AM Ham TransmitterX
    68Transmissor Assadeira 1  ES  Bancada In Spanish; schematics and pictures only  [In Spanish. English here] 386GW6AM Ham TransmitterX
    69Transmissor Assadeira 2  ES  Bancada In Spanish.  [In Spanish. English here] 35P31AM Ham TransmitterX
    70Simple FM Transmitter  DE  Alfa Lima Int. Schematic only  [In German. English here] 22EC92,EL95AM Ham TransmitterX
    7150C5 PW Transmitter  US  AM Window AM transmitter. Schematic only. 3150C5 (4)AM Ham TransmitterX
    72Five Watt Series Modulated Rig  US  AM Window They say: Only 3 or 4 crystals could cover the entire AM Window on 75 Meters" 426KE8,6AQ5AM Ham TransmitterX
    73Broadcast Band Transmitter  US  Antique Wireless Pulls a lot of punches to stay within Part 15 276AK5, 6BE6AM Ham TransmitterX
    74One Stage MW Receiver  DE  Radio Sammlung Schematic is at first link  [In German. English here] 16EF89, EL95AM Receiver0-V-1
    75MW Audion with Tiltable Star Coils  DE  Roehrenkramladen Click Schaltbild" or "Diagram" for schematic"  [In German. English here] 21ECL80AM Receiver0-V-1
    760-V-1 Mit Zwei EF98  DE  Franzis.DE “0-V-1 with Two EF98 Tubes”. Chassis is a wooden carrying box; see picture of batteries inside (filament battery plus three 9V batteries for B+).  [In German. English here] 21EF98(2)AM Receiver0-V-1
    77Récepteur OC à tube  FR  F5ZV From French. Interesting breadboard approach.  [In French. English here] 12ECC86AM Receiver0-V-1
    78Volksempfängerin People Receiver  DE  Radio Remembered Schematic link is about 1/5 of the way down the page.  [In German. English here] 18REN904, RES164AM Receiver0-V-1
    790-V-2 Audion  DE  Franzis.DE I don't understand that antenna circuit.  [In German. English here] 22ECC81AM Receiver0-V-2
    80Roehren Audionna  MS Electronics His first instinct in finding period parts was to break into houses in search of"; but shopping was easier.  [In German. English here] 246D6, 75, 42, 80AM Receiver0-V-2
    812 Röhren Audion ab 12 Volt verwendbar  DE  Raimund Hilz Picture Only.  [In German. English here] 12[-]AM Receiver1-V-1
    82Zweiröhren-Einkreisempfänger "Largo"   DE  Jogis Roehrenbude “2-tube One-stage Receiver named 'Largo'”. There is a table of different usable tubes.  [In German. English here] 32Pentode(2)AM Receiver1-V-1
    83Piccolo 58 - ein Batterie-Einröhren-Einkreisempfänger  DE  Jogis Roehrenbude In German. Single-tube battery-powered single-stage receiver.  [In German. English here] 113A5AM ReceiverBattery Powered
    84Battery Powered Radio  DE  Roehrenfreak Kind of hard to read the images.  [In German. English here] 23DF96(2),DL96AM ReceiverBattery Powered
    85Battery - Audion 1925  DE  Roehrenfreak I don't think there is a schematic with this, but the parts are beautiful  [In German. English here] 10DF96(3)AM ReceiverBattery Powered
    86Replica of Hülsmeyer's coherer receiver of ˜ 1904/05   NL  German Comm Another coherer. Looks like it would be fun.  [In German. English here] 1[-]AM ReceiverCoherer
    87Edouard Branley's Coherer  FR  F3WM The pictures should be enough to build a replica 1[-]AM ReceiverCoherer
    88The Crystodyne Principle  US  Early Radio History From Radio News; 1924. Not sure I fully get this. 8[-]AM ReceiverCrystodyne
    89Tube detector of Juergen Heisig  DE  Elektronic Bastelbude Third to last project on page. Uses a 6D6A sub-micro diode tube.  [In German. English here] 56D6AAM ReceiverDetector
    90Detektor Receiver  DE  Raimund Hilz Picture Only.  [In German. English here] 5[-]AM ReceiverDetector
    91Modern detector receiver  DE  Trommeltier Several examples  [In German. English here] 5[-]AM ReceiverDetector
    92Early detector receiver  DE  Trommeltier See last schematic on page for tube version.  [In German. English here] 730AM ReceiverDetector
    93AM Receiver with Pencil Tube and Spider Coil  JP  BB Radio Uses subminiature tube (5678); and spider coil. Low parts count  [In Japanese. English here] 165678(3)AM ReceiverDetector
    94Detector receiverna  MS Electronics He replaces the semiconductor diode with a tube.  [In German. English here] 7AZ1AM ReceiverDetector
    95Detector Receiver  FR  JC Jardine I like the use of color in schematics to show circuits.  [In German. English here] 930AM ReceiverDetector
    96Circuits FI pour récepteurs AM/ FM  FR  Dede 75007 Circuits for receivers.  [In French. English here] 43ECH81, EF80, EABC80, EM80AM ReceiverDirect Conversion
    97The Viet Cong Home Brew sets  US  EC47 History Site No schematic (although there are references to possibilities); but interesting commentary and pictures 20[-]AM ReceiverDirect Conversion
    98Telefunken Radio; 1934  DE  Ferromel 1934 Radio  [In German. English here] 18REN916, RENS1376dAM ReceiverDirect Conversion
    99Polish AM Receiver from 1947na  Fonar In Polish.  [In Polish. English here] 30EF12, ECL11AM ReceiverDirect Conversion
    100Polish AM Receiver from 1947na  Fonar In Polish. Check out the barouque coils and transformers.  [In Polish. English here] 35EBF11, ECL11AM ReceiverDirect Conversion
    101Pocket Tube Radio  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 196AB8AM ReceiverDirect Conversion
    102Pocket Tube Radio  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 306WC5,6F7AM ReceiverDirect Conversion
    103Zweikreis-Empfänger für Mittelwelle  DE  Jogis Roehrenbude In German. Two stage AM Receiver  [In German. English here] 33EF80, ECL86AM ReceiverDirect Conversion
    104" Giant 3NF" - OE333-Nachempfundenen Receiver  DE  Jogis Roehrenbude Really great photos of a "tube" constructed from an empy glass vessel and filled with 3 vacumm tubes and assorted parts. Then used to create a receiver.  [In German. English here] 17EC92(2),EL95AM ReceiverDirect Conversion
    105Bauanleitung für einen Nostalgie-Einkreiser  DE  Jogis Roehrenbude Relatively straightforward design; different style of breadboard  [In German. English here] 2078, EL2AM ReceiverDirect Conversion
    106The Straight Receiver  DE  Jogis Roehrenbude Seems to be a discussion of the limits and possibilities  [In German. English here] 21AF7,RES164AM ReceiverDirect Conversion
    107License Plate Radio  US  Antique Radios Just guessing on the circuit; as I don't see a bandspread capacitor; or any civilized attempt at a tickler winding. 106AG7(2)AM ReceiverDirect Conversion
    108Battery receiver with the DCC90  DE  Radio Freak An update of a tinkering article" from a German publication of 1960. Originally used a 3A5 tube.  [In German. English here] 10DCC90AM ReceiverDirect Conversion
    109MW Audion mit EF98  DE  Old Radio World Single tube AM Receiver. No schematic; but you don't need one from the photo.  [In German. English here] 4EF98AM ReceiverDirect Conversion
    110Battery-operated audion receiver (0-V-2) for medium wave  DE  DK3WI Uses Russian pencil tubes.  [In German. English here] 361SH29B(3)AM ReceiverDirect Conversion
    111Einkreiser mi ECC85 Doppeltriode  DE  Radio Sammlung Student project.  [In German. English here] 12ECC85AM ReceiverDirect Conversion
    112Bettery-operated German Army Radio  DE  Radio Sammlung Conversion of an existing receiver; it looks like.  [In German. English here] 33DCH11, DF11 (2), DAF11, DL11AM ReceiverDirect Conversion
    113Zweikreiser mit ECC88 und EL95  DE  Radio Sammlung Two-stage with ECC88 and EL95  [In German. English here] 13ECC88, EL95AM ReceiverDirect Conversion
    114Mein Radiomann  DE  Kurzwellen Horen No schematic; but you can figure it out from the photo. Tube added later (EF98); see text.  [In German. English here] 6EF98AM ReceiverDirect Conversion
    115Receiver with EM84 Tuning Tube  CZ  Dave Schmarder (Last project on page) Nice looking; from Czechoslovakia. Uses magic eye tube  [In Czech. English here] 8EM84AM ReceiverDirect Conversion
    116Receiver with EM83 tube  CZ  Dave Schmarder (First project on page) Nice looking; from Czechoslovakia  [In Czech. English here] 14EM83AM ReceiverDirect Conversion
    117MW Receiver  CZ  Dave Schmarder (Second on page) Nice looking; from Czechoslovakia  [In Czech. English here] 146H16bAM ReceiverDirect Conversion
    118G Marconi’s 1-valve radio  AU  Silicon Chip First project on the page 93V4AM ReceiverDirect Conversion
    119Receiver with Loewe 3NF "integrated circuit"   NL  Tatjavanvark [Fifth project down]. Highly machined: What happens when a real artist builds a tube receiver. No schematic; I don't feel I deserve one.  [In Dutch. English here] 133NF(10)AM ReceiverDirect Conversion
    120Improved Radio for the Model T  US  Cool 386 Yes, that Model T 2612AT7, 6CS6, 6AQ5AM ReceiverDirect Conversion
    121Kleinst-Radioempfänger "Mucki"   DE  Jogis Roehrenbude “Small Radio-Receiver Named 'Mucki'”. Strange do-it-all tube (UCH4) which is a hexode and triode.  [In German. English here] 25VY1, UCH4AM ReceiverDirect Conversion
    122Der Nachbau eines Loewe OE 333  DE  Jogis Roehrenbude “Building the Loewe OE333”. LOTS of pictures and details. Check out the last photos (tube mounted on rock base).  [In German. English here] 7OE333AM ReceiverDirect Conversion
    123Versaerker mit induktive Ruckkoppung  DE  Erinacom “Amplifier with Inductive coupling”.  [In German. English here] 7EF98AM ReceiverDirect Conversion
    124Rückkopplung nach dem ECO-Prinzip   DE  Erinacom “Back Coupling to the ECF Principal” Whatever that is.  [In German. English here] 7EF98AM ReceiverDirect Conversion
    1252 Tube AM Radio  JP  Ya2_com Scroll to the right.  [In Japanese. English here] 256BZ6,6AQ5AAM ReceiverDirect Conversion
    126Mittelwellenradio mit R90CC  DE  Franzis.DE “AM Receiver with E90CC”. Uses and IC-based audio amplifier after the E90. Only 6V on the plate  [In German. English here] 16E90CCAM ReceiverDirect Conversion
    127Radio Craft Solar  US  Dipsey Dumpster Booklet for boys from 1922. The photo on page 10 alone is worth the download. Several detailed plans for a “loose coupler”. 4[-]AM ReceiverDirect Conversion
    128One-Tube “Wallop”  US  de Bellefeuilles Recevier from Popular Electronics, 1955. The tube, 1D8, does the work of three tubes. Increment the file number to see succeeding pages. 121D8GTAM ReceiverDirect Conversion
    129ONE TUBE MATCHBOX AM RADIO  US  N2ZHS Kind of cute. 51S4AM ReceiverDirect Conversion
    130Single sphere radio which used the spider coil  JP  BB Radio Actually; the tube is a subminiature pencil tube; not a sphere  [In Japanese. English here] 75678AM ReceiverDirect Conversion
    131Continuous Wave Receiver  DK  OZ6GH Basic receiver, with a local oscillator. So two tubes. 10[Triode](2)AM ReceiverDirect Conversion
    132Simple Use of Triode as Detector  DK  OZ6GH Three different schematics, with discussion of approaches 7[Triode]AM ReceiverDirect Conversion
    133German Broadcast Receivers, 1924, Part 1  DK  OZ6GH Several different pictures; showing tremendous over-engineering 6[Triode]AM ReceiverDirect Conversion
    134German Broadcast Receivers, 1924, Part 2  DK  OZ6GH More pictures and more tremendous over-engineering; see part 1 6[Triode]AM ReceiverDirect Conversion
    135Postes Reception Portatifs  DK  OZ6GH Four different 1920's era circuits for French receivers that were portable  [In French. English here] 7[Triode]AM ReceiverDirect Conversion
    136Stations of Direct Amplification  FR  JC Jardine You'll have to do some work on this schematic to fill in values  [In French. English here] 30[-]AM ReceiverDirect Conversion
    137227 Type Homemade Cathedral Radio in (1933-1935)  JP  AJR Translated from Japanese.  [In Japanese. English here] 16UY-227,UY-112A,KX-112BAM ReceiverDirect Conversion
    138Early Time Battery Tube Radio During (1925-1935)  JP  AJR Translated from Japanese. Scroll to bottom for schematic.  [In Japanese. English here] 6NVV-6AAM ReceiverDirect Conversion
    139Two bands 1v2 Straight Receiver  JP  AJR Translated from Japanese. Remember 1-V-2 means 1 RF amplifier; a detector; then 2 audio amplifiers. I think.  [In Japanese. English here] 2412K7,12SJ7,12J5,12A6AM ReceiverDirect Conversion
    1401925 French AM Receiver  FR  F5AGK I guessed at the tubes.  [In French. English here] 1630 (4)AM ReceiverDirect Conversion
    141Kratkovalvolina Audion (0-V-0) with EF183  SL  B Zupan I'm guessing at the language here.  [In Slovenian. English here] 17EF183AM ReceiverDirect Conversion
    142The Smallest Radiomann  DE  B Kainka Uses a subminiature tube. Notice the connector for the variable capacitor.  [In German. English here] 136021AM ReceiverDirect Conversion
    143Radiomann  DE  B Kainka A classic. In Germany; at least.  [In German. English here] 13ECC82AM ReceiverDirect Conversion
    144The KC1-Batterieradio  DE  B Kainka Experiments with Telephone receiver speaker  [In German. English here] 11KC1AM ReceiverDirect Conversion
    145Radiomann  DE  B Kainka Start here for a description of the German classic.  [In German. English here] 1312AU7AM ReceiverDirect Conversion
    1462V4-Audio  DE  Jogis Roehrenbude 2.4 Volts on the plate. Pretty cool; as the filament is only 2.2 volts.  [In German. English here] 62SH27PAM ReceiverDirect Detection
    147N1NKM's 1-tube BTN AM Radio  US  My Morninglight From N1NKM. Looks like that tube is doing a lot of different things. 3015BD11AM ReceiverDirect conversion
    148Audio Receiver  DE  Radio Freak Original audion circuit.  [In German. English here] 66K5AM ReceiverDirect conversion
    149Double-tuned Crystal Set  US  N9VV Double tuned" is big. And I like those knobs. 6[-]AM ReceiverDouble Tuned
    150Electromechanical RF Receiver for VLF  US  World of LF 18 Khz. Site has an excellent photo, and a RealAudio clip of an actual reception with the device. 6[-]AM ReceiverElectromechanical
    151Workshop One Sphere Radio  JP  Radio Sammlung From Japanese. Good pictures and diagrams for a very simple circuit. Submini tube. Great approach to homebrew coil. Only needs 9V on plate.  [In Japanese. English here] 65678AM ReceiverGrid Detector
    152Grid detection: Space charge tetrode  JP  Sleeping Vacuum Translated from Japanese. Breadboard radio with explanation of theory of this kind of detection.  [In Japanese. English here] 9UX-54AM ReceiverGrid Detector
    153Röhren-Detektorempfänger  DE  Jogis Roehrenbude In German. Simple detector radio. Who needs a chassis; anyways?  [In German. English here] 12EAA91AM ReceiverGrid Leak
    154Roehren Audion / Tube Receiver  DE  Radiobasteln 1st project on page  [In German. English here] 7EF97AM ReceiverGrid Leak
    155Breadboard AM-er - A Golden Oldie  US  Crystal Radio Basic circuit 627AM ReceiverGrid Leak
    156Un Receptor Adecuado  US  Crystal Radio Basic circuit. From Chile? 627AM ReceiverGrid Leak
    157Grid-Leak 1-tube Receiver  US  Fun With Tubes A lot of useful theory and background on grid leak detectors. 116AU6AM ReceiverGrid Leak
    158Hi-Fi AM Radio  AU  Elliot Sound [Scroll down articles page to article on AM Radio]. Quite and eye-opener. See the charts in the middle of the page. 5[-]AM ReceiverHi-Fidelity AM
    1591920's Interflex Receiver  US  Glowbugs Basically; a crystal receiver with a 30 tube added 5[-]AM ReceiverInterflex
    160Magnetic Detector  US  N9VV Circa 1902- 1912 6[-]AM ReceiverMagnetic Detector
    161Marconi's Magnetic Detector.  DK  OZ6GH Article describes how Rutherford was able to detect radio waves up to ¾ mile using magnetized needles. 4[-]AM ReceiverMagnetic Detector
    162Negadyne Recevier  DE  Jogis Roehrenbude Some discussion on how (whether?) this works.  [In German. English here] 9EF83AM ReceiverNegadyne
    1635-tube Neutrodyne Receiver  US  Dipsey Dumpster Actually, there are half a dozen different circuits and radios in this booklets, the neutrodyne is the last but highlight for general oddity value. 1501A(5)AM ReceiverNeutrodyne
    164Hazeltine’s Neutrodyne Radio Receiver (1923)  US  Antique Radio I like the way these JPG pages are laid out on an HTML page. 20UV-200, UV-201AAM ReceiverNeutrodyne
    165Pocket Tube Radio  JP  Tube Pocket Radios Nice pocket picture! Fun packaging; too. Site in English and Japanese. Main page:  [In Japanese. English here] 206BH6,6AB8AM ReceiverReflex
    166Pocket Tube Radio  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 201T4(2)1DN5AM ReceiverReflex
    1672-tubes reflex super-het using Russian sub-mini tubes  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 201J24B,1J29AAM ReceiverReflex
    168ST-Tube Pocket Radio  JP  Tube Pocket Radios The ST tubes in a pocket package are a foot. Uses DC-DC converter. Site in English and Japanese. Main page:  [In Japanese. English here] 201E7G,1F6AM ReceiverReflex
    169Eines Einröhren - Reflexempfängers  DE  Jogis Roehrenbude In German. From 1927. Looks like a technology dead-end. What was the point of this one?  [In German. English here] 9RE084AM ReceiverReflex
    170Two Tube Reflex Receiver  DE  Jogis Roehrenbude From German. Looks to be 1920's era.  [In German. English here] 14EAF42,EL41AM ReceiverReflex
    1712 Rohren Reflex Empfanger  DE  DL9EBA Two Tube Reflex Receiver. Uses Russian tubes.  [In German. English here] 242Sh24PAM ReceiverReflex
    172How to Build a Two Valve Set  UK  Nat'l Valve Museum Looks like an instruction article from the mid-1920's. Lots of pictures and very detailed 12PM1,PM2AM ReceiverReflex
    1731-tube reflex receiver  US  Dave Schmarder Dave Schmarder. Highly recommended site. 141J6AAM ReceiverReflex
    174ACME 4-tube Reflex Broadcast Receiver (1924)  US  Spark Bench Restoration project. Lots of photos 16201AM ReceiverReflex
    175Acme Reflex BCB Receiver  US  Spark Bench I'm not sure what all the term "reflex" implies. 1601A(4)AM ReceiverReflex
    176Single sphere reflex super  JP  Portable Translated from the Japanese  [In Japanese. English here] 226U8AM ReceiverReflex
    177Amplifier Stage for AM Receiver  JP  Sleeping Vacuum I like the line when excessively terrible omission is done; sphere flies and/or there is a possibility the house burning". Ah; Babelfish.  [In Japanese. English here] 5UX-245AM ReceiverReflex
    178Reflex (Triode/Pentode)  JP  Sleeping Vacuum There are a lot of tubes that can do this.  [In Japanese. English here] 166F7AM ReceiverReflex
    179With 0-V-1 radio gymnastics  JP  Sleeping Vacuum Or use a 19 tube; etc.  [In Japanese. English here] 8UZ-30MCAM ReceiverReflex
    180Diode-Triode Reflex Receiver: Radio-Craft 1932  JP  Sleeping Vacuum Scroll to the bottom of the page.  [In Japanese. English here] 1585AM ReceiverReflex
    181Relex Radio  JP  Sleeping Vacuum Part of this site's walk through the history of tube rigs. Uses a tree stump for a breadboard; sort of.  [In Japanese. English here] 123z-DH3AAM ReceiverReflex
    182“Knock-Out” Reflex Receiver  US  Dipsey Dumpster A magazine article from 1923 or so. Looks like there are several different approaches. 7TriodeAM ReceiverReflex
    183One-Tube Reflexed Regenerative Receiver  US  Photobucket Schematic only. What makes it reflex? 630AM ReceiverReflex
    184Reflex receiver of 1925 (Germany)na  MS Electronics You can tell that schematic symbols had not been standardized by 1925. Are those resistors or coils? I like his discussion of replacement parts.  [In German. English here] 10A408AM ReceiverReflex
    185Homemade Three Tube Reflex Radio in 1930-1932/1930-1932  JP  AJR Translated from Japanese.  [In Japanese. English here] 18UY-226,UX12AAM ReceiverReflex
    186Interflex tube design  US  Crystal Radio Six pages. Change iflex1" to 'iflex2"; etc. 12216AAM ReceiverReflex
    187Battery-Powered One-Tube Receiver  JP  Museum of Craft Runs on 9V and 4.5V batteries  [In Japanese. English here] 1512AU7AM ReceiverReflex
    188The Russian Liliput - an MW audion with 3 * 12SH1L  DE  Elektronic Bastelbude Translated from German.  [In German. English here] 2212SH1LAM ReceiverRegenerative
    189Basic Regenerative Receiver (In Spanish)  ES  Crystal Radio Net In Spanish on JPG file; so the translators are useless  [In Spanish. English here] 8A110AM ReceiverRegenerative
    190Amplifier added to Flashlight Battery Set  US  Jeff Duntemann From Popular Mechanics; Late 1930's 949(2)AM ReceiverRegenerative
    191The Elf; a 2-Tube Set for the Beginner  US  Jeff Duntemann From Radio-Craft; August; 1936 1049(2)AM ReceiverRegenerative
    192Simple AM Regenerative  US  Jeff Duntemann A lot of radios on this page; scroll down and follow the link to a schematic. 93V4AM ReceiverRegenerative
    193Low Voltage Regenerative Receiver Using Mains Voltage Valves  UK  G4JCP From DL4OBG. Uses certain regular tubes at 12V on plate; not space charge tubes. 2012AU7(2)AM ReceiverRegenerative
    194Low Voltage Receiver  UK  G4JCP They aren't kidding: 4.5 volts on the plate. 9P220(2)AM ReceiverRegenerative
    195EF50 Receiver  UK  G4JCP 22EF50(2)AM ReceiverRegenerative
    196Original Armstrong Regenerative Radio  US  Biosensers Here it is; Armstrongs original circuit straight from the patent application 710AM ReceiverRegenerative
    197Sanford and Son (junkbox) radio  US  HP Friedrich's This is the man who wrote Voice of the Crystal, and Instruments of Amplification 106AU6AM ReceiverRegenerative
    198Self-Build AM Receiver Kit  DE  Jogis Roehrenbude Enough information here – schematic, pictures, materials, etc. - to duplicate the commercial version.  [In German. English here] 121T4AM ReceiverRegenerative
    199Before the Radiomann; there was the Ur-Radiomann  DE  Jogis Roehrenbude I like the variable coupling on the coils. Also the battery box at the bottom of the page. Notice on the first schematic the virtual absence of labels  [In German. English here] 9RE034, RE084AM ReceiverRegenerative
    200Regen Built By 12-year Old  CA  Joystick From a magazine article (included) on building a one-tube emergency radio. 81S5AM ReceiverRegenerative
    201Audion Receiverna  Radiomann Another radiomann style receiver. Notice the hand-fabricated components  [In German. English here] 8EF98AM ReceiverRegenerative
    202Improved Hikers One Setna  NZ Vintaqe Radio Good drawings and construction explanations. 9V B+. 749AM ReceiverRegenerative
    203Browning-Drake Receiver  US  Old Radio Builder Many radios on this website and they are are HOT! 1730(3)AM ReceiverRegenerative
    204Two-Tube Regenerative Set  US  Old Radio Builder B+ is 22 to 45 V. Tubes are 30's. Interstage transformer. 1130(2)AM ReceiverRegenerative
    205One-Tube Regen  US  Antique Radios The power supply is interesting (see picture) 96V6AM ReceiverRegenerative
    206Replica of Air Champ AC-100  US  K5BCQ Replicating a popular kit from the 1950's. 73Q4AM ReceiverRegenerative
    207Battery Powered Tube Regenerative Receiver  US  K5BCQ K5BCQ asks How would I improve the AC-100?" 261T4,1U4,3S4AM ReceiverRegenerative
    208Workshop One Sphere Regenerative  JP  Radio Sammlung Second project halfway down page. Good pictures and diagrams for a very simple circuit. Submini tube. Great approach to homebrew coil. Only needs 9V on plate.  [In Japanese. English here] 65678AM ReceiverRegenerative
    209Single triode regenerative.  US  Dave Schmarder Dave Schmarder. Highly recommended site. 930AM ReceiverRegenerative
    210Two-tube BCB Regenerative  US  Dave Schmarder Dave Schmarder. Highly recommended site. 171T4 (2)AM ReceiverRegenerative
    2113Q5 regenerative receiver  US  Dave Schmarder Dave Schmarder. Highly recommended site. 113Q5AM ReceiverRegenerative
    212A 2-valve miniature  AU  Silicon Chip Second project on the page 171T4,3V4AM ReceiverRegenerative
    213One Tube Regenerative  AU  Australian Vintage From an Australian Source. Doesn't get much simpler 81T4AM ReceiverRegenerative
    214Braodcast Band Regenerative  US  Spark Bench Cool-looking tube holders 121T4,1S5,3S4AM ReceiverRegenerative
    215Hikers Two BCB Regenerative  US  Spark Bench Based on two space charge tubes. Uses one 1.5V battery, and one 9V battery. Tunes 3-12 MHz. 1149(2)AM ReceiverRegenerative
    216Twin Triode Regenerative Receiver  US  SubDevo From N4JVP 1512AT7AM ReceiverRegenerative
    217Geradeausempfaenger (Straight-Through Receiver)  DE  Trommeltier I like the way he explains in detail what is going on in the circuit. Just about any tube can be experimented with here.  [In German. English here] 8[-]AM ReceiverRegenerative
    2184-tube Regenerative Receiver  CA  Vintage Ham Very nice construction techniques 21222 (2), 201A (2)AM ReceiverRegenerative
    219Regenerative Radio Using a 1625 Tube  US  Tom Kipgen's The whole thing runs on a 12V wall wart. Nice tube for that. Schematic is at 81625AM ReceiverRegenerative
    220Regenerative AM Receiver  JP  Ya2_com Translated from the Japanese  [In Japanese. English here] 256BN6,6AW8AM ReceiverRegenerative
    221PENTA-2008, ein Röhrenaudion mit der EF95  DE  Franzis.DE “Penta-2008, a tube receiver with the EF95”. There's a quick enclosure! What's with the two antennas?  [In German. English here] 10EF95AM ReceiverRegenerative
    222Tube Type 30 Regenerative Receiver  US  Photobucket Schematic only. 630AM ReceiverRegenerative
    223Early 1920's Regenerative  FR  Riethmuller First project on the page (there are two more below it)  [In French. English here] 14201A (?)AM ReceiverRegenerative
    224French regenerative detectors  FR  Riethmuller A lot of history goes with the page.  [In French. English here] 10C119AM ReceiverRegenerative
    2256C4-6C 42 sphere radio  JP  BB Radio Interesting.  [In Japanese. English here] 196C4(2)AM ReceiverRegenerative
    2266BJ6-6AK 62 sphere radio  JP  BB Radio Clean construction; uses AM radio parts to make . . . an AM Radio!  [In Japanese. English here] 226BJ6, 6AK6AM ReceiverRegenerative
    227One tube regenerative radio  US  Boatanchors As simple as they get 731AM ReceiverRegenerative
    228Détectrice à réaction  FR  F5LVG From a French journal; a simple one-tube receiver. Page also has schematics for 2;3 and 4 tube receivers  [In French. English here] 730AM ReceiverRegenerative
    229Triodes Predating De Forest's  DK  OZ6GH Four early tubes and receiver schematics based on them: (a) X-Ray tube, (b) Coolidge tube,(c) Von Lieben tube and (d) Wehnelt tube 5[Triode]AM ReceiverRegenerative
    230ST tube 3 sphere radio  JP  BB Radio Common circuit.  [In Japanese. English here] 1977,41AM ReceiverRegenerative
    231Variations on Vacuum Valve Regenerative  DK  OZ6GH Eleven different variations, to be exact. From a 1919 article. 8[Triode]AM ReceiverRegenerative
    232The Weagent Undamped Receiver  DK  OZ6GH From early 1920's. A type of regenerative receiver. 8[Triode]AM ReceiverRegenerative
    233Four Tube Eliminator Radio in 1930s  JP  AJR Translated from Japanese.  [In Japanese. English here] 1526(3), 27AM ReceiverRegenerative
    234Anntena-Less 1-Tube Regenerative Receiver  US  Crystal Radio But you have to connect it to a water pipe . . . 530AM ReceiverRegenerative
    235Regenerative Detector  US  Fun With Tubes Simple; with tips for beginners. 126AU6AM ReceiverRegenerative
    236Twin Triode Regenerative Receiver  US  Arcs and Sparks Available as a kit. No schematic, but the circuit should be basic. 126A6AM ReceiverRegenerative
    237Das Pentoden-Audion  DE  B Kainka Simple version of MW receiver using 12J1L  [In German. English here] 1012J1LAM ReceiverRegenerative
    238One Tube Regenerative Receiver  US  Big Nick's From Alfred Morgan's First Book of Radio and Electronics. Probably any Triode (6C5; etc.) will do. 96BF6AM ReceiverRegenerative
    239Einfachst aufzubauender 1-Stunden-Empfänger mit einer Subminiatur-Röhre  DE  Jogis Roehrenbude In German. One-hour radio with subminiature tube  [In German. English here] 82E32AM ReceiverSubminiature tubes
    240Super-Regenerative Receiver  US  Lindsay's Technical Reprint from Lindsay Books 1910AM ReceiverSuper regenerative
    241AAF pencil tube superheterodyne  US  ElectronixAndMore Sooner or later someone was going to try this. Great pictures. 465702 (3), 5704, 6111AM ReceiverSuperheterodyne
    242Original Armstrong Superheterodyne Radio  US  Biosensers Scroll down a little from the regenerative to see the handwritten original schematic for a superheterodyne. 2010(4)AM ReceiverSuperheterodyne
    2433 Bands; 5 Valves Radiona  TPS Schematic only. Mature AM Radio 33UCH81, UF89, UBC81, UL84, UM84AM ReceiverSuperheterodyne
    2441971 Era BCB Superhet  JP  Shoranosekai On a Japanese site; in English. See for main link page to internals and schematic.  [In Japanese. English here] 386BE6, 6BA6, 6GW8AM ReceiverSuperheterodyne
    245Pocket Tube Radio  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 241AG4,CK533AXAM ReceiverSuperheterodyne
    246Pocket Tube Radio  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 261AG4,1AJ5,CK526AXAM ReceiverSuperheterodyne
    247Pocket Tube Radio  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 3112FR8AM ReceiverSuperheterodyne
    248Gachapon capsule 3 tubes reflex super het  JP  Tube Pocket Radios A superhet built inside a round plastic capsule. Gachapon machines are small vending machines of toys."  [In Japanese. English here] 265678(3)AM ReceiverSuperheterodyne
    249Pocket Tube Radio  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 205678,1V6AM ReceiverSuperheterodyne
    2503-SmT tubes reflex super het  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 265678,1AJ5,1AG4AM ReceiverSuperheterodyne
    251Pocket Tube Radio  JP  Tube Pocket Radios Site in English and Japanese. Main page:  [In Japanese. English here] 224-SmT(2)AM ReceiverSuperheterodyne
    252Perverse Fellows Radio  JP  JF10ZL His design approach was apparently to use the "wrong" tube for each stage.  [In Japanese. English here] 456AR5,6BE6,6BD6,6AV6AM ReceiverSuperheterodyne
    253Amplifier for MW AM RADIO Receiver  JP  JF10ZL Maximizes use of a double tube  [In Japanese. English here] 426AN8(2)AM ReceiverSuperheterodyne
    254Ein Einbereichs-Super - Selbstgebaut  DE  Jogis Roehrenbude In German. Self-built suerheterodyne. Check out that AK2 tube. You were expecting two pins?  [In German. English here] 42AK2, REN904, RES164AM ReceiverSuperheterodyne
    255Zweiröhren-Superheterodyne-Empfängers für Mittelwelle  DE  Jogis Roehrenbude In German. AM 2-Tube Receiver  [In German. English here] 32ECH87, EL84AM ReceiverSuperheterodyne
    2564 Röhren Audion mit Miniatur Röhren  DE  Raimund Hilz Picture Only.  [In German. English here] 20[-]AM ReceiverSuperheterodyne
    257Build a Minidyne (miniature superheterodyne)  US  de Bellefeuilles Popular Science; 1956; single tube reflex receiver 256U8AM ReceiverSuperheterodyne
    258AM FM Tuner  AU  Cool 386 Seems a bit much work 386K7,12AT7,6J7,6SC7,6CM7AM ReceiverSuperheterodyne
    259All American 5 sub-mini tube AM radio; what if?  US  WA2ISE Pencil tube modified All-American 5 4512BE6,5702,5703,5898,50C5,35W4AM ReceiverSuperheterodyne
    260compAA3 Compactron AM tube radio  US  WA2ISE Weird tubes. (Filaments add up to 58V; or half of 117V). 3711AR11(2), 8B10, 38HK7AM ReceiverSuperheterodyne
    261Portable Battery Superhet Receiver  NL  Trevor Gale's Second project on the page. 301R5, 1T4, 1U4, 3S4AM ReceiverSuperheterodyne
    2625 battery bulb tube two-way radio super high  JP  Bearwalk From Japanese. This is an odd one. Kind of a rack-mount clear plastic wall unit of a radio. Note that the loop antenna is wrapped around the box itself.  [In Japanese. English here] 321T4(2), 1R4, 1U4, 3S4AM ReceiverSuperheterodyne
    2631 super high-tube bulb battery 5 portable radio  JP  Bearwalk From Japanese. Clear plastic cube, maybe 7" on a side. It looks like the fit a whole AA5 into that thing.  [In Japanese. English here] 271T4(2), 1R4, 1U4, 3S4AM ReceiverSuperheterodyne
    264A 4-Tube Minimal Space-Charge Superhet  JP  Portable In Japanese  [In Japanese. English here] 3012AD6, 12EZ6, 12AE6, 12K5AM ReceiverSuperheterodyne
    265BCB AA-5 superhet; made with space-charge tubes  JP  Portable In Japanese  [In Japanese. English here] 3612AF6(2),12AE6,12AG6,26A6(2),12K5AM ReceiverSuperheterodyne
    2664 Spheres One Way Portable Receiver  JP  Portable Translated from the Japanese  [In Japanese. English here] 25DK96,DF96,DAF96,DL96AM ReceiverSuperheterodyne
    2675 spheres 2 way Portable Receiver  JP  Portable Translated from the Japanese  [In Japanese. English here] 281LN5, 1LA6, 1LN5, 1LD5, 3LF4AM ReceiverSuperheterodyne
    2686 Sphere Magic Eye Attaching Portable  JP  Portable Translated from the Japanese  [In Japanese. English here] 301AH5, 3C4, 1AB6, 1H3, 1AJ4(2)AM ReceiverSuperheterodyne
    2699 sphere 2 band high 1 2 receiver  JP  Portable Translated from the Japanese  [In Japanese. English here] 533E6(2), 1LN5 (3), 1LA6, 1LC6, 1LD5, 3LF4AM ReceiverSuperheterodyne
    2704 sphere 2 bands portable  JP  Portable Translated from the Japanese  [In Japanese. English here] 443Y4, 1AH5, 1T4, 1l6AM ReceiverSuperheterodyne
    2714 spheres super / American type  JP  Portable Translated from the Japanese  [In Japanese. English here] 3612AD6, 12EZ6, 12AE6, 12K5AM ReceiverSuperheterodyne
    272Miniature Tube Portable Superheterodyne Receiver  JP  Portable Using 45V B" Supply  [In Japanese. English here] 331R5,1T4,1S5,1S4AM ReceiverSuperheterodyne
    273Miniature Tube Portable Superheterodyne Receiver  JP  Portable 1960's version from RCA Receiving Tube Manual  [In Japanese. English here] 281R5,1U4,1U5,3V4AM ReceiverSuperheterodyne
    274My First Catalin  US  Solitaire Not really a homebrew project; alhough the schematic is here. Is that a dog to the left of the girl in the picture at the top; or a shadow? 251R5, 1T4, 1S6, 3S4AM ReceiverSuperheterodyne
    275mT tube transformerless 5 sphere super  JP  BB Radio All-American 5 Tube lineup  [In Japanese. English here] 3612BE6,12BD6,12AV6,35C5,35W4AM ReceiverSuperheterodyne
    276All-British Seven-Valve Superheterodyne  DK  OZ6GH Full article reproduced from period magazine in 1920's 28[Triode](7)AM ReceiverSuperheterodyne
    277Two Tube Radio Operated with DC 24v  JP  AJR Translated from Japanese.  [In Japanese. English here] 2812AU7(2)AM ReceiverSuperheterodyne
    278Superheterodyne with ECH83  SL  B Zupan I'm guessing at the language here.  [In Slovenian. English here] 34ECH83, PCF802 (2)AM ReceiverSuperheterodyne
    279The All American Five - A Circuit Walkthrough  US  Fun With Tubes This is a fun read. Article explains the cost considerations that drove the design 4012BE6,12BA6,12AV6,50C5,35W4AM ReceiverSuperheterodyne
    280Synchrodyne AM Receiver  NL  A Van Waarde No coil! I snuck in a transistor circuit because I wondered if this could be done in a tube version. 21[-]AM ReceiverSynchrodyne
    281Home Brew Two Tube Farm Radio  US  Grandads Electronics From Grandad's Electronics (scroll to bottom of page) 323A8GT, 1D8GTAM ReceiverSynchrodyne
    282Grid detection: Triode  JP  Sleeping Vacuum Translated from Japanese. Great page! He shows a half-dozen pictures of antique tube types running in the circuit.  [In Japanese. English here] 10111BAM ReceiverTriode
    2831920's Dutch Homebrew  NL  Piet Hoen AM receiver. No schematic; but it’s a TRF. Notes say the poor guy never got it working. 18A409 (3), B406AM ReceiverTuned Radio Format
    284Exray's Radio LL Super Baby Restoration  US  Spark Bench Radio LL was an important French Radio. Author made replacment tubes for the French originals using 5676's. 26A441(4),B406AM ReceiverTuned Radio Format
    285Monocyte radio 6J6  JP  BB Radio From Japanese. Breadboard AM Receiver  [In Japanese. English here] 196J6AM ReceiverTwo-Stage
    2866C4-2 radio sphere 6AQ6  JP  BB Radio From Japanese. Breadboard AM Receiver  [In Japanese. English here] 186C4, 6AQ6AM ReceiverTwo-Stage
    287Tube-based VLF recevier  IT  VLF I'm not sure how to classify a project like this; but it looks like a good introduction to VLF where the origins of the signals are geological.  [In Italian. English here] 24ECC82AM ReceiverVLF
    288Variometer-based Receiver  IT  Le Radio de Sophie In Italian. Nice looking piece.  [In Italian. English here] 14124AM ReceiverVariometer-Based
    289Various homebuilt radios  US  Glowbugs Looks like possible Popular Mechanics or Popular Electronics. One bug PDF file with about 25 radios. Should break this up. 20[-]AM ReceiverVarious
    290Low cost progressive receivinfg  US  Crystal Radio Net Built on slats 76J6AM ReceiverX
    291One Tube Emergency Receiver  US  Crystal Radio Net Subminiature tube 81S5AM ReceiverX
    292One Tube Emergency Receiver  US  Crystal Radio Net Uses one subminiature tube 71S5AM ReceiverX
    293A 12FR8 Pocket Tube Radio  JP  Tube Pocket Radios In Japanese. Pretty wild tube (diode/triode/pentode)  [In Japanese. English here] 3313FR8AM ReceiverX
    294Batterie-Empfänger mit der Röhre 3 B 7  DE  Jogis Roehrenbude Battery-Powered AM Receiver with 3B7 tube. This thing is SMALL.  [In German. English here] 113B7AM ReceiverX
    2954-Röhren-Empfänger mit der RV 12 P 2000.  DE  Jogis Roehrenbude Quite elaborate. From 1947. In German.  [In German. English here] 38P2000 (4)AM ReceiverX
    296Dreiröhren-Audion für ca. 300 - 1600 m Wellenlänge  DE  Jogis Roehrenbude In German. Lots of discussions about the coils.  [In German. English here] 15RE084 (3)AM ReceiverX
    2976SN7GT-based AM Receiver  DE  Jogis Roehrenbude A Danish translation of a US Popular Mechanics article; from a German web site. No frills.  [In German. English here] 86SN7GTAM ReceiverX
    298Einkreis-Empfänger mit der ECC 86  DE  Jogis Roehrenbude In German. Pencil-size; miniature tubes.  [In German. English here] 12ECC86 (2)AM ReceiverX
    299Fahrrad - Super  DE  Jogis Roehrenbude In German. Bicycle-based AM Receiver  [In German. English here] 24P700 (4)AM ReceiverX
    300Röhrenradio nach historischem Vorbild  DE  Jogis Roehrenbude Tube radio with nostaligic interest.  [In German. English here] 48ECH81, EF86, EL84AM ReceiverX
    301Einfach aufzubauender 4-Röhren-Empfänger mit 2 HF-Vorstufen  DE  Jogis Roehrenbude In German. Looks like something out of Flash Gordon.  [In German. English here] 12VariousAM ReceiverX
    302Audion mit verbesserter Klangqualität  DE  Jogis Roehrenbude In German. High quality audio in AM receiver.  [In German. English here] 10EABC80AM ReceiverX
    303American Junkbox Receiver  DE  Jogis Roehrenbude In German. What it says.  [In German. English here] 1912AT7, 35CWAM ReceiverX
    304Kofferradio mit Batterie-Röhren  DE  Jogis Roehrenbude Radio with Battery-based Tubes"  [In German. English here] 16DF96, DL96AM ReceiverX
    305Radio-RIM - Bausatz Piccolo 49 - ein Batterie-Einröhren-Einkreisempfänger  DE  Jogis Roehrenbude In German. Small; battery-powered radio.  [In German. English here] 10P700 (2)AM ReceiverX
    306Einfaches Taschen-Radio mit einer Rröhre  DE  Jogis Roehrenbude In German. Simple tube-based pocket radio.  [In German. English here] 6P700AM ReceiverX
    307UKW-Pendelempfänger  DE  Jogis Roehrenbude In German. I can't tell if this is a converter or just a tuner/preamplifier. Ideas?  [In German. English here] 26EF41, EF42AM ReceiverX
    308Batterie-Einkreisempfänger für's Wochenende  DE  Jogis Roehrenbude In German. Weekend Battery Radio.  [In German. English here] 13DF91, DAF91AM ReceiverX
    309Carolina 96  IT  Le Radio de Sophie I can't tell if this was a real porduct in the 1940's; or a retro-projection. Anyone know Italian?  [In Italian. English here] 256SK7, 6SQ7, 6V6AM ReceiverX
    310Radio reazione  IT  Le Radio de Sophie Gets my vote for one of the most beautiful. Note the butterfly mounted in the center of the loop antenna  [In Italian. English here] 86KTGAM ReceiverX
    311RX with picture antenna with ECL82  IT  Le Radio de Sophie In Italian. Uses triode/pentode (the ECL82)  [In Italian. English here] 17ECL82AM ReceiverX
    312Build your own AM Tuner  US  Bruce C Hi-Fi Tuner and Amplifier; From 1950. 526SK7, 6AS7, 6K7, 6C5, 6J5, 6146, 5Y3AM ReceiverX
    313DOERLE 2-TUBE RADIO  US  Philco Repair Classic design from 1937 Hammarlund Shortwave Manual 1530 (2)AM ReceiverX
    314Multi-Radio Radio  US  Dave Schmarder Mr. Schmarder enters his Baroque period 241625 (2)AM ReceiverX
    31512AF6 broadcast band radio  US  Dave Schmarder Dave Schmarder. Highly recommended site. 1112AF6AM ReceiverX
    316Homemade Single Tube Breadboard Radio.  US  Dave Schmarder From Dave Schmarder 601AAM ReceiverX
    3174-tube receiver  US  Dave Schmarder Dave Schmarder. Highly recommended site. 281T4 (2), 1S5, 3S4AM ReceiverX
    318Prayudi's 12AF6 / LM386 Radio built in Indonesia  US  Dave Schmarder First one on page. Uses LM386 audio circuit 912AF6AM ReceiverX
    3192 Valve Set: Little Jim's Mate Plus Audio Section  AU  Australian Vintage What is Little Jim's Mate"? An Australian classic? 141J6G,1L5GAM ReceiverX
    320Hi-Fi AM Tuner  US  de Bellefeuilles Popular Science; 1958 136SK7AM ReceiverX
    321GEC A.C. Mains 4  UK  Wireless Works An AM Receiver 186AU6 (?) (3)AM ReceiverX
    3223-Tube Common Receiver  JP  Hu Amp These tubes have common replacements. Translated from the Japanese  [In Japanese. English here] 19UZ6C6,6ZP1AM ReceiverX
    323Average Three Radio  JP  Portable Translated from the Japanese  [In Japanese. English here] 1877,41AM ReceiverX
    324Like original work three radio  JP  Sleeping Vacuum Translated from the Japanese.  [In Japanese. English here] 156C6,6ZP1AM ReceiverX
    32512SN7 single sphere radio   JP  Sleeping Vacuum Translated from the Japanese.  [In Japanese. English here] 1512SN7AM ReceiverX
    3260-V-0 with EF97 Audio  DE  Radiobasteln 4th project on page  [In German. English here] 14EF97AM ReceiverX
    327Am Receiver with Active Antenna  DE  Radiobasteln 3rd project on page  [In German. English here] 23ECC40, ECL80AM ReceiverX
    328AM Receiver (German)  DE  Radiobasteln 2nd project on page  [In German. English here] 12EF86, EL95AM ReceiverX
    329Battery receiver with ECC85 and EL95  DE  Radio Sammlung In German. No schematic; but interesting contruction approach.  [In German. English here] 16ECC85, EL95AM ReceiverX
    330Picture Radio  DE  Radio Sammlung In German. Simple AM Receiver.  [In German. English here] 13ECC85AM ReceiverX
    331Globe radio.  DE  Radio Sammlung In German. Not sure how to classify this one. Novelty seems too strong.  [In German. English here] 16ECC85, EC92AM ReceiverX
    332Circuit for Crystal Radio With One Tube Amplifier  US  Scottswim Second half of the page 630AM ReceiverX
    333Meissner 10-1106 Broadcast TRF receiver kit  US  Boatanchors Kit radio introduced with an article in the June 1937 issue of Radio-Craft magazine 256K7(2), 6J7, 6F6AM ReceiverX
    3341929 two-tube AM receiver  US  Boatanchors Nice use of original parts 1130 (2)AM ReceiverX
    335Beacon Simplidyne (AM Receiver)  AU  M Van Emmerik 5 tubes. A triumph of coil design"! 19A409 (4), A415 (1)AM ReceiverX
    336RCA Prep Kit Radio  US  Reverse Time Schematic printed right on the board 81T4AM ReceiverX
    337Adler Portable: M.Adler  UK  Vintage Radio See also file circuit.jpg". From 231R5,1T4,1G5AM ReceiverX
    338Attachecase Portable: 1R5 1T4 1S5 3S4: F.C.Warren  UK  Vintage Radio See also file circuit.jpg". From 281R5,1T4 1S5 3S4AM ReceiverX
    339Compact 4+1: ECH42 Z77 DH77: D.H.Nash  UK  Vintage Radio See also file circuit.jpg". From 40ECH42,Z77,DH77AM ReceiverX
    340Garnerbike: 1R5 1U4 1U5 3V4: L.E.Garner  UK  Vintage Radio See also file circuit.jpg". From 301R5,1U4,1U5,3V4AM ReceiverX
    341Mini Four Midget Portable: DK91 DF91 DAF91 DL92  UK  Vintage Radio See also file circuit.jpg". From 25DK91,DF91,DAF91,DL92AM ReceiverX
    342Miniset: DK96 DF96 DAF96 DL96: S.E.Addis  UK  Vintage Radio See also file circuit.jpg". From 30DK96,DF96,DAF96,DL96AM ReceiverX
    343Repanco Hi gain SH4 (Courtesy of Ron Bryan)  UK  Vintage Radio No article with this one. 406K8,6K7,6Q7,6V6AM ReceiverX
    344Rowley Two: 2G22 2E32 2E42 2E36: A.Rowley  UK  Vintage Radio See also file circuit.jpg". From 202G22,2E32,2E42,2E36AM ReceiverX
    345Rowley One: 1R5 1U4 1S5 1S4: A.Rowley1  UK  Vintage Radio See also file circuit.jpg". From 351R5,1U4,1S5,1S4AM ReceiverX
    346Submini: 2G21 2G31: W.A.Kumm  UK  Vintage Radio See also file circuit.jpg". From 252G21,2G31,CK505 (3)AM ReceiverX
    347Supermidget: 1R5 1T4 3S4: T.A.Blanchard  UK  Vintage Radio See also file circuit.jpg". From 251R5,1T4,3S4AM ReceiverX
    348One tube interflex radio  US  Ricks Place Elegant arrangement. No schematic 630AM ReceiverX
    349Six Volts Works this Blackout Set  US  Crystal Radio Fits in a lunch box; it appears 96G6-G (2)AM ReceiverX
    350Single tube radio that runs on flashlight cells  US  Crystal Radio Another Popular Science-type article 101S4AM ReceiverX
    351Two-Tube Mini-Pal AM Receiver  US  Crystal Radio Fits in a small file box. 103S4AM ReceiverX
    352Single tube radio you can mail  US  Crystal Radio The whole thing is flat; so it can be mailed in 6x9 envelope. Cute. 82E32AM ReceiverX
    353Boy Scout Receiver  US  AL7FS See article. 83A4AM ReceiverX
    354Boy Scout Radio Merit Badge Receiver  US  AL7FS Is there still a Radio merit badge? 83A4AM ReceiverX
    355Four tube radios for beginners  US  Crystal Radio Change feb1" to "feb2" to see second page 1570L7GTAM ReceiverX
    356Printed Radio Circuits  US  Crystal Radio Interesting; probably the first; printed circuit for hobbyists (1940's). Note small version in picture. 10CK505-AX (2)AM ReceiverX
    357Two Tube Super Battery Set For Vacations  US  Crystal Radio More Popular Science. Nice tableaux of boy scout and dad. 221R5, 1U5AM ReceiverX
    358The De Forest D-12 Radiophone  US  Antique Radio I'm glad someone invented symbolic schematics 19D-12 (4)AM ReceiverX
    3591-tube radio (5678)  JP  Vacuum Tube Radio Very miniature tube; the 5678 (Cost about $3 each)  [In Japanese. English here] 65678AM ReceiverX
    360One-Tube AM Receiver  JP  Museum of Craft Japanese  [In Japanese. English here] 1812AU7AM ReceiverX
    361Das Dampfradio mit der ECC86  DE  B Kainka Six volts on the plate.  [In German. English here] 10ECC86AM ReceiverX
    362Radiomann umsockeln: Die EF95  DE  B Kainka Great tube socket idea at the bottom of the page.  [In German. English here] 15EF95AM ReceiverX
    363Radiomann-Umbau mit PCL86  DE  B Kainka Radiomann Built from PCL86  [In German. English here] 15PCL86AM ReceiverX
    3646888 Transmitter  US  Antique Radios AM Transmitter. Scroll down to see a nice picture. 86888AM Transmitter1 Watt
    365Self-Oscillating 7AK7 Transmitter  US  Antique Radios Made me want to run out and buy a sheet-metal brake. 177AK7AM Transmitter1 Watt
    366Pirate Amplitude Modulated Transmitter 1600-1800KHz  CR  Dragan Nikolic Hand-drawn schematic. Apparently really used as a pirate station (see text). 50PF86,PCF80,PL36,PL509AM Transmitter100 Watts
    36715W Toy FM Transmiiter.  CR  Dragan Nikolic Schematic only 14EL34AM Transmitter2 Watts
    368Schematic Only  US  WJ5MH Phonograph Oscillator, Wireless Broadcast Transmitter 2512J5,12SA7AM Transmitter2 Watts
    36980/40 CW Transmitter with 6BM8/ECL82  RU  Antentop PDF File. 80/40 CW Transmitter with 6BM8/ECL82 21ECL82AM Transmitter2 Watts
    370Transmitter for 136 Khz  US  World of LF Uses four PL519's. The variometer is a bucket from a Chinese restaurant (see photo on bottom of page). 300W output 18PL519(4)AM Transmitter300W
    3715-Meter Transceiver for Newcomers  US  Glowbugs AM modulation. From Frank Jones handbook of the 1930's 2041,76AM Transmitter5 Meters
    372AM Messsender  DE  Bastelprojekte Messsender?  [In German. English here] 31PC91,ECH84AM Transmitter5 Watts
    373One Tube Transmitter  US  Photobucket Screen Modulation with Carrier Control. Schematic only. 186M11AM TransmitterCompactron
    374RF Alternator Transmitter  US  MJ Rainey Run the alternator to get 48 Khz. A recreation of “Fessendens Christmas Broadcast” 6[-]AM TransmitterElectromechanical
    375600 Watts Vodulator with 2 X 813  NL  Radio Morningstar Scheamtic only. 23813(2)AM TransmitterModulator
    376Poulsen Arc Modulator  DK  HeltHansen Goes back to 1903. Now that's a primitive transformer!  [In Danish. English here] 9[-]AM TransmitterPaulson Arc
    377One-Tube Wireless Rebroadcaster  US  de Bellefeuilles A simple AM transmitter. From Popular Electronics, 1963. Increment the file number to see succeeding pages. 812AT7AM TransmitterSimple
    3787AK7 One-Tube Transmitter  US  Photobucket From R. Weaver. On Photobucket 157AK7AM TransmitterSimple
    379One Tube Transmitter, 6JV8 Version  US  Photobucket From R. Weaver. On Photobucket 166JV8AM TransmitterSimple
    380AM Transmitter  US  Photobucket Compactron Tube. Schematic Only. 1112SA7AM TransmitterSimple
    381Lafayette Wireless Broadcaster  US  Photobucket Schematic only. 2550BM8(2)AM TransmitterTransformerless
    3822 x 40 W Valve amplifier with Active Grid Biasing  NL  Tjaco's Design Parts count is for both channels 32ECC81, EL84 (4)Audio Power AmpActive Grid Bias
    383Audio Amplifier  US  Clarisonus From November 1951 Electronics" Magazine 136AS7G(2)Audio Power AmpCathode Follower
    3842A3 Single Ended cathode follower drive amplifier  JP  Single Ended What's with the background of this web page? 196U8, 2A3Audio Power AmpCathode Follower
    385Amplifier “RADIO LAMPA” with 22 tubes 2SH27L  DE  Jogis Roehrenbude 22 tubes make sense; if they are very small; and you have enough time on you hands to over-engineer something like this. Bravo!  [In German. English here] 652SH27L(22)Audio Power AmpClass A
    386My first tube amplifier  US  Gabe's Tube Amps Intended for use as a separate state to have around for radio use. Good walk-through of technical design principles. 712AX7Audio Power AmpClass A
    387Beam power tube EL504  DE  B Kainka Similar to his PL504 Verstarker; but allows switching from triode to pentode modes. Also different packaging.  [In German. English here] 14EL504(2)Audio Power AmpClass A
    388Stereo amplifier; four times PL504  DE  B Kainka Nice tall; thin power tubes with improvised (?) caps for a cool new look.  [In German. English here] 12PL504(2)Audio Power AmpClass A
    389Voorversterker gebouwd rond de B406 DHT  NL  Gydotron In Dutch; I believe  [In Dutch. English here] 1712HG7,B406Audio Power AmpMu-follower
    390Mu-stage voorversterker rond de 6H23; 692   NL  Triode Store In Dutch; I believe  [In Dutch. English here] 206H23Audio Power AmpMu-follower
    391Ciuffon Andrea Amplifier  IT  Mattij's Tube Schematic. I like the hand-drawn schematic.  [In Italian. English here] 3512AX7, 5687, 6C33CAudio Power AmpOTL
    392Philips High Impedance Speakers  UK  Vintage-Radio Philips was attempting to eliminate the need for an output transformer in the output circuit 7UCL82Audio Power AmpOTL
    393Low Voltage OTL Amplifier  US  T Williams Schematic only. Oh; and I snuck in some transistors. 1312B4Audio Power AmpOTL
    394Horizontal Sweep Tube OTL  US  T Williams How to string along the 6CD6's in parallel; the more the merrier 326SJ7, 6AQ5, 6CD6 (3)Audio Power AmpOTL
    395Parallel Cathode Follower Amplifier  US  T Williams How to string along the 6DK6's in parallel; the more the merrier 2212AU7, 6DK6 (3)Audio Power AmpOTL
    39612B4 OTL Amplifierna  Bonavolta Schematic only. 246AU6, 6S4, 12B4 (2)Audio Power AmpOTL
    397EL86 OTL Amplifierna  Bonavolta Schematic only. 13EL86 (2)Audio Power AmpOTL
    398Single Ended EL84na  Setiawan Audio In Indonesian. I can't read a word of this, and there seems to be some Dutch thrown in.  [In Indonesian. English here] 10EL84Audio Power AmpOne Stage
    3992A3 PSE - Parallel Single Ended  IT  Audio Design Guide Is this really the right title? 105842, 2A3 (2)Audio Power AmpParallel SE
    400OTL Amplifierna  Audiovn Club First project on the page  [In Vietnamese. English here] 226SJ7, 6SN7, 6080Audio Power AmpParallel SE
    401Power Amplifier with Four PL519  DE  Roehrensockel I can't really follow the point here. Is he saying he's using a low voltage transformer? Or what?  [In German. English here] 43PCL82,PL519Audio Power AmpParallel
    402Power output stage with 4 PL519  DE  Roehrensockel For Low Impendance Transducers.  [In German. English here] 43PCL82, PL509 (4)Audio Power AmpParallel
    403Stereo integrated 845 SE amp  BE  DIY Paradiso 6DN7 is similar to 6EA7. And I love the looks of the 845! 256DN7 (2), 845 (2)Audio Power AmpPush Pull
    404RA-100 Integrated Amplifier  DK  Fred Nachbaur Monster project by Fred Nachbauer. Puts us all to shame. 19112AX7 (4), 12AT7 (4), 6CB6 (2), 6L6 (4), 0B2 (2)Audio Power AmpPush Pull
    405Dogzilla Power Amp  DK  Fred Nachbaur 200 Watts powered by six 807's 316SN7, 807 (6)Audio Power AmpPush Pull
    406High-Fidelity Tube Amplifier  US  E Tuttle From the RCA Receiving Tube Manual 3212AU7, 6AU6 (2), 6V6 (2)Audio Power AmpPush Pull
    407Push-Pull Class A 2A3 Stereo Amp  US  Bob Danielak Last paragraph describes invasion of his garage by Keith; Mick and company 336SL7,6SN7,2A3(2)Audio Power AmpPush Pull
    408Push-Pull Class A 2A3 Stereo Amp  US  Bob D Nice writeup on his experiments with modifications 346SL7,6SN7,6L6Audio Power AmpPush Pull
    409A 6080/6AS7G-Verstärker  DE  Jogis Roehrenbude Why the extra tube?  [In German. English here] 29ECC81, 6189, 6080 (2)Audio Power AmpPush Pull
    410Mamont (aka Mammoth; Mamoet, Mammut ...) power amp  RU  Klausmobile Was built around Atma-Sphere M-60 design". But I have to admit I can't tell what is going in with this schematic.  [In Russian. English here] 356SN&(8)Audio Power AmpPush Pull
    41160 Watt Audio Power Amplifier  ES  LU8EHA Schematic only. For a photo; click the link at the bottom of the page and slect Foto for this project.  [In Spanish. English here] 506AN8, KT88 (2)Audio Power AmpPush Pull
    412Martin Logan SL3 direct-coupled tube poweramp  NL  Machmat Whew! Even the speaker (I think . . .) is part of the schematic. 48E180F, 6EM7 (2), SV572-3Audio Power AmpPush Pull
    413Official Stromberg-Carlson APH-1050 Shrine  US  OPCOM's Conversion of a PA system to a HiFi Amplifier 256GH8, 6CD6 (2)Audio Power AmpPush Pull
    414Balanced low-Z mic/line amp with TUBES  US  OPCOM's Balanced line amplifier. Schematic only. 1812AU7 (2)Audio Power AmpPush Pull
    415Tube Stereo Booster Amp for Car  US  OPCOM's 50 Watts. And look! Dynamotors! 86146Audio Power AmpPush Pull
    416Darling variant  US  Tim Reese's Another Darling Amplifier 226dJ8, 1626(2)Audio Power AmpPush Pull
    4172 x EL95 Verstarket II  DE  Bastelprojekte Push pull amplifier  [In German. English here] 38ECC83(2),EL95(2)Audio Power AmpPush Pull
    418Battery Powered Amplifier  DE  Bastelprojekte B+ is a block of 11 x 9V batteries, filament is 4 x 1.2V NiCads  [In German. English here] 29DC90(2),DL94Audio Power AmpPush Pull
    419ECL82'er  DE  Bastelprojekte Push pull amplifier  [In German. English here] 25ECL821(2),ECL82(2)Audio Power AmpPush Pull
    420ECL82'er  DE  Bastelprojekte ECL82 = 6BM8. There is an auxiliary preamp at the bottom of the page (5 parts)  [In German. English here] 33ECL82 (2)Audio Power AmpPush Pull
    421EL84 Mark I  DE  Bastelprojekte Another EL84 amplifier.  [In German. English here] 30ECC83(2),EL84Audio Power AmpPush Pull
    422PP Amp Using Iron Concertina Phase Splitter  US  Jeremy Epstein Interesting circuit. Author has some ideas on the transformer 1812B4, 2A3Audio Power AmpPush Pull
    423High Fidelity Amplifier with No Phase Distortion Up to 30 KHzna  Radau5 (PDF File) Uses acorn tubes and other unusual approaches. And what is that CRT doing? 25954(3),955,CRTAudio Power AmpPush Pull
    424Projekt Mono 845  DE  Roehrenfieber Looks like the prototype for a commercial product  [In German. English here] 346DN7, 845Audio Power AmpPush Pull
    425Ultralinear Amp with EL508  DE  Roehrensockel Quite involved power supply.  [In German. English here] 39EF86, ECC83, EL508 (2)Audio Power AmpPush Pull
    426171A class A push-pull amplifier  JP  Sugimoto's Uses tubes from 20's and 30's.  [In Japanese. English here] 24227(2),171A(2)Audio Power AmpPush Pull
    427171A Push Pull Amplifier  JP  Sugimoto's All tubes from the 20s and 30s 21227 (2), 171A (2)Audio Power AmpPush Pull
    4286EM7 Push Pull Amplifier  JP  Single Ended In English with Spanish commentary 286AQ8,6EM7(4)Audio Power AmpPush Pull
    4296EM7 Push Pull Amplifier  ES  Single Ended Interesting approach.  [In Spanish. English here] 276AQ8, 6EM7 (2)Audio Power AmpPush Pull
    430Ten Watt Triode Amplifier  US  Triode Store Schematic only. 246AV6, 6CG7, 6BX7Audio Power AmpPush Pull
    431LEAK POINT ONE AMPLIFIER  UK  HJ Leak From a 1945 article. 33EF36,ECC33,KT88(2)Audio Power AmpPush Pull
    4326CA7 PP (EL34) all bump dynamic experiment Amplifier  JP  Bearwalk From Japanese. Another clear plastic box, but very extensive and complex. Pretty cool looking.  [In Japanese. English here] 23ECC83, EL34(2)Audio Power AmpPush Pull
    43316A8 in Push Pull configuration  JP  Passionate Tube Push Pull with a triode/pentode acting as drivers and power amps.  [In Japanese. English here] 1616A8 (2)Audio Power AmpPush Pull
    4346AH4 in Push Pull configuration  JP  Passionate Tube Uh; Oh; another MOSFET in the name of science. All projects on this site have a publication page" with discussion.  [In Japanese. English here] 316FQ7, 6AH4Audio Power AmpPush Pull
    435Experimental Amplifier  JP  Passionate Tube Strange circuit.  [In Japanese. English here] 206BQ7, 6AU6, 6V6Audio Power AmpPush Pull
    43625CD6 Amplified  JP  Hu Amp Story and schematic.  [In Japanese. English here] 3012AT7, 12AX7, 25CD6Audio Power AmpPush Pull
    4372xEL34 Hi-End Amplifier  NL  HB Thui(s)brouw In Dutch, I believe  [In Dutch. English here] 21ECC83, EL34(2)Audio Power AmpPush Pull
    438Power Amplifier 2x15 Watts for 800 Ohm Speaker  SE  Ake's Website Apparently a popular amplifier in Sweden in the 1960's 25ECC83, EL86(2)Audio Power AmpPush Pull
    439Two Ultralinear UNCH with EL84  RU  Radiostation.RU Translated from Russian. Not sure I got this.  [In Russian. English here] 266H23P,EL84(2)Audio Power AmpPush Pull
    440Amplifiers of 15 to 30 Watts  US  Tube Zone PDF file. Uses “the three beam pentodes, KT55, KT66, KT88”. 366J5, KT66(2)Audio Power AmpPush Pull
    44160 Watt Amplifier with KT77  US  Tube Zone PDF file with charts, etc. 28ECC82, KT77Audio Power AmpPush Pull
    4426L6 Amp by 'Rutcho'  ES  IGA Valves Schematic only. 32ECC81(4), 6L6(2)Audio Power AmpPush Pull
    443Another 6L6 Amp by 'Rutcho'  ES  IGA Valves Schematic only. 27ECF80, 6L6(2)Audio Power AmpPush Pull
    44460 Watt EL34 Amp  ES  IGA Valves Schematic only. 325879, 6CG7, EL34(2)Audio Power AmpPush Pull
    4456B4 Amp  ES  IGA Valves Schematic only. 196SN7(3), 6B4Audio Power AmpPush Pull
    446Corft Series 5 Valve Power Amplifier  ES  Alex's Page Push Pull amplifier. 34ECC83, EL84(4)Audio Power AmpPush Pull
    447EL802 Spud Amplifier  US  Pete Millet's Interesting circuit and breadboard project. 9EL802(2)Audio Power AmpPush Pull
    4486V6 Amplifier with 6SN7's  JP  Electron Tube Index Minimal text with schematic  [In Japanese. English here] 246SN7(2), 6V6(2)Audio Power AmpPush Pull
    4491KW Audio Amplifier  US  Nat'l Valve Museum Looks rather beefy. 12EL37(2), MZ2-200(2)Audio Power AmpPush Pull
    4506CA7 Push Pull Amplifier  JP  Shimosan In Japanese  [In Japanese. English here] 325187(2), 6189(2), 6AC7(2)Audio Power AmpPush Pull
    4516BM8 Push Pull Amp  JP  Shimosan In Japanese. One tube per channel  [In Japanese. English here] 206BM8(2)Audio Power AmpPush Pull
    4526EM7 Single Ended Amp  JP  Shimosan In Japanese. Small parts count and very compact (see photo of rig under a lamp).  [In Japanese. English here] 136EM7Audio Power AmpPush Pull
    453New EL34 Parallel Amp  IT  Audio Design Guide That's how I do breadboards! 2612AX7, 6SN7, EL34(4)Audio Power AmpPush Pull
    454PCL805 Roehren Kopfhoererverstarker  DE  Jogis Roehrenbude “PCL805 Tube Headphone Amplifier”. Inlcudes printed circuit diagram, full parts list, etc.  [In German. English here] 52PCL805(2)Audio Power AmpPush Pull
    455Gegentakt-Verstärker in AB-Betrieb für GU 50   DE  Jogis Roehrenbude “Push-Pull Amplifier for GU50”. Nice, beefy-looking tubes  [In German. English here] 486SN7(2), GU50(2)Audio Power AmpPush Pull
    45630 Watt-Stereo-Endstufe mit 4 x EL 84   DE  Jogis Roehrenbude “0-Watt Stereo Output Amplifier with 4 x EL84”  [In German. English here] 42ECC83, EL84(4)Audio Power AmpPush Pull
    457Der Dickie-Makovski – Verstärker   DE  Jogis Roehrenbude “The Dickie-Makovski Amplifier”. Apparently from a radio show in the 1950's. No output transformer needed.  [In German. English here] 3212AT7(2), 6SN7, 6080(6)Audio Power AmpPush Pull
    458Oldie-Verstärker  DE  Jogis Roehrenbude “Oldie Amplifier”  [In German. English here] 22AC2(2), AD1(1)Audio Power AmpPush Pull
    459Röhren-Gegentaktverstärker mit der EL 51   DE  Jogis Roehrenbude “Tube-Push Pull Amplifier with EL51”. An all-pentode lineup.  [In German. English here] 34EF86(2), EL51(2)Audio Power AmpPush Pull
    46012-Watt-EL84-Verstärker   DE  Jogis Roehrenbude “12-Watt EL84 Amplifier”  [In German. English here] 27ECC83, EL84(2)Audio Power AmpPush Pull
    461140-Watt-Röhren-Verstärker mit 4 x EL 34 - "The Rocker"   DE  Jogis Roehrenbude “140 Watt Tube Amplifier – The Rocker”. Shaped like an automobile engine, and very shiny.  [In German. English here] 6512AX7, 12AU7, EL34(4)Audio Power AmpPush Pull
    462Gegentaktverstärker mit Niederspannungsröhren   DE  Reinhard Stenzel “Push-Pull Amplifier with Low Voltage Tube.” This is a small, amplifier for the 12K5 low-voltage tube.  [In German. English here] 1412AU7, 12K5Audio Power AmpPush Pull
    463Gegentaktverstärker mit Subminiaturröhren   DE  Reinhard Stenzel “Push-Pull Amplifier with Subminiature Tubes”. Cute and small.  [In German. English here] 326112(2), 5092(2)Audio Power AmpPush Pull
    464Dreikanal-Stereoverstärker "ORCHESTER"   DE  Reinhard Stenzel “Three-channel Stereo Amplifier”. Uses a bunch of subminiature tubes in an impressive little formation.  [In German. English here] 326021(2), 5092(2)Audio Power AmpPush Pull
    465Röhrenverstärker mit ECC82 und EL84   DE  Frank Moller “Tube Amplifier with ECC82 and EL84”. Nice pictures. Push-pull. 3 Watts.  [In German. English here] 21ECC82, EL84Audio Power AmpPush Pull
    466Acrosound 6-50 Monoblocke  DE  Jogis Roehrenbude A 4 x EL34 Amplifier.  [In German. English here] 366SN7(2), EL34(4)Audio Power AmpPush Pull
    467Symmetrischer 6L6-Gegentaktverstärker   DE  Jogis Roehrenbude “Symmetrical 6L6 Push-Pull Amplifier”. This version uses metal tubes.  [In German. English here] 186SJ7(2), 6L6(2)Audio Power AmpPush Pull
    4684 x PCL86-PP - Amp   DE  Jogis Roehrenbude Nice color, whatever it is. Looks like the PCL86 is a triode/pentode.  [In German. English here] 22PCL86(4)Audio Power AmpPush Pull
    469EL504 Gegenversaerker  DE  Roehrenbastler “EL504 Push Pull Amplifier”.  [In German. English here] 10EL504Audio Power AmpPush Pull
    470PCL82 Gegenversaerker  DE  Roehrenbastler “PCL82 Push Pull Amplifier”.  [In German. English here] 16PCL82(2)Audio Power AmpPush Pull
    47135W Tube Power Amplifier with EL34na  Sam's Circuits Apparently from a Seimens and Haskle design of 1953  [In Greek. English here] 24E80CC(2), EL34(2)Audio Power AmpPush Pull
    4723W Tube Power Amplifier with 6BX7na  Sam's Circuits Commentary in Greek  [In Greek. English here] 19ECC81, 6BX7Audio Power AmpPush Pull
    473EL34 Push Pull Amp  US  Photobucket Schematic only. 2012AX7, EL34Audio Power AmpPush Pull
    474Push-Pull 845  FR  Magnetic Free Antenna coupler 306J5, R130, 845 (2)Audio Power AmpPush Pull
    475813 Matrix Amplifier  US  Analog Engineer Minimal discussion 166BM8, 813 (2)Audio Power AmpPush Pull
    476600 Watt Audio Modulator  NL  Radio Morningstar Schematic Only. 800 Watts  [In Dutch. English here] 19EL84, EL34 (2), 810 (2)Audio Power AmpPush Pull
    477Audio Amplifier with 2x807  NL  Radio Morningstar Schematic Only. 120 Watts  [In Dutch. English here] 126L6, 807 (2)Audio Power AmpPush Pull
    478Push Pull Tube Amp  US  Gabe's Tube Amps I like his comments about the sound of the music and examples of good sources. Movie cartoons as a sound source! 196EU7, 6BQ5 (2)Audio Power AmpPush Pull
    479Parallel Push Pull Amplifier  DE  A-Freak Translated from the German  [In German. English here] 22ECC83,EL34(2)Audio Power AmpPush Pull
    4806B4 PP Amp  US  Fi Primer See the text discussion at 206SN7, 6DJ8, 6B4 (2)Audio Power AmpPush Pull
    4816CK4 Direct-Coupled PP Amplifier  US  Fi Primer See the text discussion at 1212BZ7 (2), 6CK4 (2)Audio Power AmpPush Pull
    482807 Ultralinear PP Amp  US  Fi Primer See the text discussion at 246SL7, 6DJ8, 807 (2)Audio Power AmpPush Pull
    483Basic Audio Amplifier  NL  Erik Putz In English and Dutch.  [In Dutch. English here] 30ECC83,EL84Audio Power AmpPush Pull
    48431LQ6 Push Pull Amplifier  US  T Williams Proof that those weird tubes might be worth something 156EA8, 6DJ8, 31LQ6 (2)Audio Power AmpPush Pull
    485AhA! 2a3 Push-Pull amplifier  NL  Aha! Based on JE labs Stereo pp2a3" 206SN7(2),2A3(2)Audio Power AmpPush Pull
    48615 Watts for 12AB5; 12SL7  US  Beans Amps Schematic only. 3412AB5, 12SL7Audio Power AmpPush Pull
    487Push Pull Amplifier  IT  Paeng Design Schematic; parts list; and some results.  [In Italian. English here] 136C45(2)Audio Power AmpPush Pull
    488Stereo Miniamp  JP  Vacuum Tube Radio From Japanese. Apparently a Japanese kit. Cost looks to be about $200.  [In Japanese. English here] 276BM8 (2)Audio Power AmpPush Pull
    4892A3 Push Pull Amplifierna  Bonavolta Schematic only. Main index is 2312AU7, 6C4 (2), 2A3 (2)Audio Power AmpPush Pull
    4906146 Push Pull Amplifierna  Bonavolta Schematic only. 20 Watts 256SN7 (2), 6146 (2)Audio Power AmpPush Pull
    4916L6 Push Pull Ampna  Bonavolta Schematic only. 20 Watts 246SL7, 6SN7, 6L6 (2)Audio Power AmpPush Pull
    492Double Push Pull 6V6 Ampna  Bonavolta Schematic only. Double push pull cathode follower. 286SN7 (2), 6V6 (4)Audio Power AmpPush Pull
    493807 Push Pull Amplifierna  Bonavolta Schematic only. From 1949. 346SN7 (2), 807 (2)Audio Power AmpPush Pull
    49425L6 Power Amplifier Without Power Transformer  US  Free Info Society Certainly a low parts count; I'd be afraid of all those electrons trying to get back to ground . . . 1612SN7,25L6(2)Audio Power AmpPush-Pull
    4952 x 50 watts Tube Power Amplifier  DE  Klaus Boening Four stages, really. This design is quite a hybrid.  [In German. English here] 52ECC81,ECC82,ECC83,KT88Audio Power AmpPush-Pull
    496Amplifier with EL84  FR  M Terrier EL84 = 6BQ5  [In French. English here] 1912AX7, 6BQ5Audio Power AmpPush-Pull
    497Restauro LEAK TL/12 Point One  IT  Audio Construzioni At least it looks like an amplifier to me.  [In Italian. English here] 43EF36, ECC33, KT66(2), GZ32Audio Power AmpPush-Pull
    498832 Transmitting Tetrode P-P Amplifier  MY  Audio Hobbyist Now that is one weird-looking tube. Kind of squat and cute"; I guess. 2712AT7,832Audio Power AmpPush-Pull
    499Battery Powered 26 Tube Amplifier  NL  VT52 Interesting discussion about what it takes to run an amplifier's B+ on batteries; and charge them; in the real world. 102C51, 26Audio Power AmpRC Loaded
    500OTL - Output Transformerless Tube Amp  IT  Audio Design Guide First project on the page 9E182CC, ECC83, 6C33 (2)Audio Power AmpSEPP
    5016EM7 SE AUDIO AMP  US  K5DKZ This is a different approach to using the 6EM7 266SN7, 6EM7Audio Power AmpSRPP + SE
    5026BM8 STC Amplifier  JP  Cambie With discussion of circuit's theory  [In Japanese. English here] 236AK5, 6BM8Audio Power AmpSTC
    5036360 Amplifier  JP  Hu Amp Translated from the Japanese  [In Japanese. English here] 2412AU7(2),6360Audio Power AmpSTC
    504Building of 6BM8 amp  JP  Hu Amp Interesting construction on a cookie can  [In Japanese. English here] 136AK5, 6BM8(2)Audio Power AmpSTC
    5056BM8 STC Amplifier  JP  Hu Amp A Whole Lot of Theory on this very long page  [In Japanese. English here] 156AK5,6BM8Audio Power AmpSTC
    506Super Triode connection Circuit (STC)  JP  S. Ito Good information. New circuit invented in the 90's" Is that true? "Stream of Era" paragraph is some of the best writing on the web. Period. 146BM8Audio Power AmpSTC
    507ECC83 / EL84 Amplifierna  El Portal I need to find an online translator for this.  [In Polish. English here] 22ECC83, EL84Audio Power AmpSingle Ended
    508Japanese 6EM7 Amplifier  JP  Ebe Ken Another version of the classic 6EM7 amp.  [In Japanese. English here] 116EM7Audio Power AmpSingle Ended
    509Power Amplifier  FR  Dede 75007 Schematic Only.  [In French. English here] 206AT6, 6AQ5Audio Power AmpSingle Ended
    510The building of a tube amplifier  DE  Christian Julius Shows some photos of vacuum tube assembly; etc.  [In German. English here] 1512AX7, EL84Audio Power AmpSingle Ended
    511A PX25 SE-power amplifier  NL  DHT Rob The Ca is an exotic tube"  [In Dutch. English here] 17Ca,PX25Audio Power AmpSingle Ended
    512Magique; a SE-project with aspirations  NL  DHT Rob Wow; this is about as obsessive on parts and design as I've seen. 6 pages.  [In Dutch. English here] 234606,45Audio Power AmpSingle Ended
    5136DN7 SE amp  MY  DIY Paradise 6DN7 is a dissimilar triode. This article makes me envious of people who seem to swim in a sea of hand-wound output transformers. 156DN7Audio Power AmpSingle Ended
    5146DN7 giant killer amp  BE  DIY Paradiso Uses only 2 tubes for stereo 156DN7Audio Power AmpSingle Ended
    515Mr. Atarashi's Parafeed Amplifier  BE  DIY Paradiso Author is critical of values and quality of components; feedback helps; but what's lost is lost". 21EF86, 6CA7, 845Audio Power AmpSingle Ended
    516Loftin White VT52 Amplifier  BE  DIY Paradiso More wry schematic commentary: Lots of parallelling of capacitors ; automatic bias everywhere" 15E83CC, VT52Audio Power AmpSingle Ended
    517845 Pramp.  BE  DIY Paradiso Author says These [Japanese] are crazy! I wish I could listen to one of these!" 15845 (2)Audio Power AmpSingle Ended
    518572-10 Triode Amplifier  BE  DIY Paradiso This circuit was apparently used by Svetlana to promote their 572-10 triode 126BM8, 572-10Audio Power AmpSingle Ended
    519Early Ultrapath Circuit Amplifier  BE  DIY Paradiso I like the relaxed circuit commentary: 0;43mA through a tube seems too little to me ; the 500 ohm resistor is just there to give you a headache " 112A6, 2A3Audio Power AmpSingle Ended
    520WE310 Jean Higara design Amplifier  BE  DIY Paradiso From Jean Hiraga's book ; la maison de l'audiophile" 14WE310, VT52Audio Power AmpSingle Ended
    521Low Cost Triode SET Amplifier  DK  Fred Nachbaur Author notes that even with new parts this amp would be under $100. 13EM7 has a 12.6V heater; see the 6EM7 913EM7Audio Power AmpSingle Ended
    522Experimental 6EM7 Amplifierna  Echoloft First message in the thread has a link to the schematic 126EM7Audio Power AmpSingle Ended
    523A Single Ended 12B4A Integrated Amplifier. 1.5 Watts.  US  Enjoy The Music Really fun walk through of the circuit and design process for this 1.5W simple amp. 116AU6, 12B4AAudio Power AmpSingle Ended
    524MONOtriodino 3 a 2a3 DHT SE amplifier  IT  Galavotti's I like the Italian sites. Everything is so exciting! Sample: from an electrical point of view (driving capabilities; band; slew rate) this was clearly outstanding SE"!  [In Italian. English here] 126SN7,2A3Audio Power AmpSingle Ended
    5256F5P SET Amplifier  US  Nizhegorodov's Lost of discussion of the effects of changing different parts. 176F5PAudio Power AmpSingle Ended
    526Single Ended Class A2 SV811-10 Stereo Amp  US  Bob D Nice complete writeup 176SL7,6SN7,6AS7,SV811-10Audio Power AmpSingle Ended
    5273V4 SE Stereo Amplifier  JP  Dad's Projects In Japanese  [In Japanese. English here] 111U5, 3V4Audio Power AmpSingle Ended
    5281626 Single Ended Amplifier  JP  Dad's Projects Preamp and power stage. Translated from the Japanese  [In Japanese. English here] 156DJ8,1626Audio Power AmpSingle Ended
    52935l6 Single Ended Amplifier  JP  Dad's Projects Preamp and power stage. Translated from the Japanese  [In Japanese. English here] 1512AX7,35l6Audio Power AmpSingle Ended
    53050BM8 Single Ended Amplifier  JP  Dad's Projects More avoidance of the power transformer  [In Japanese. English here] 1550BM8Audio Power AmpSingle Ended
    5316CS7 Single Ended Amplifier  JP  Dad's Projects Chassis is a cookie can. Translated from the Japanese  [In Japanese. English here] 116CS7Audio Power AmpSingle Ended
    532SE Audio Amplifer (English and Japanese)  JP  Shoranosekai On a Japanese site; in English. See for main link page to internals and schematic.  [In Japanese. English here] 246AN8A, 45Audio Power AmpSingle Ended
    533Clarion: A simple 2A3 Project  US  Hagerman Tech PDF file. Extensive photos and description. 16ECC89, 2A3Audio Power AmpSingle Ended
    534Tube Headphone Amplifier  IT  Headwize Very complete page - practical discussion; curves; printed circuit boards; etc.  [In Italian. English here] 126SN7, E182CCAudio Power AmpSingle Ended
    5352A3 Amplifier on a Budget  US  Gabavee Short explanation 1312AX7, 2A3Audio Power AmpSingle Ended
    536300B Single Ended Triode Mono Block Amplifierna  Walton Audio After the JE Labs version 166SN7, 300BAudio Power AmpSingle Ended
    537Single Ended Amplifier; 6C41C, 2 x 6.5 Watts  DE  Jogis Roehrenbude Has VU meters; tunings eyes; etc.  [In German. English here] 32EC8010, 6SN7, 6C41, EM84Audio Power AmpSingle Ended
    538838 SE Amp  DE  Jogis Roehrenbude Uses 6EM7 as driver tube.  [In German. English here] 236EM7, 838Audio Power AmpSingle Ended
    539“Talk Devil” - Amp  DE  Jogis Roehrenbude Why “Talk Devil”?  [In German. English here] 26ECC82, 4P1LAudio Power AmpSingle Ended
    540Amplifier SYNOLA SE845  DE  Jogis Roehrenbude I like his review of all the problems he encountered.  [In German. English here] 216FQ7, 6SN7, 845Audio Power AmpSingle Ended
    5411626 Stereo Amp  US  K5DKZ Two watts; but 'drives speakers to ear-splitting volume'. Looks solid. 186SN7,1626(2)Audio Power AmpSingle Ended
    5423 Watt SE Amplifier with 6BM8 Tube  US  Lighthouse Electric That 6BM8 keeps popping up. 166BM8Audio Power AmpSingle Ended
    5433 Watt SE Amplifier with 6BM8 Tube  US  Lighthouse Electric Lots of helpful text for beginners. Tube is also ECL82. 176BM8Audio Power AmpSingle Ended
    5444W Audio Amplifier  RU Simple circuit found in a Russian forum. Scroll 1/3 way down page.  [In Russian. English here] 23EF86, 6P1pAudio Power AmpSingle Ended
    545EL84 Output Stage  DE  Loetstelle Single-Ended Amp.  [In German. English here] 8EL84Audio Power AmpSingle Ended
    546EL 84 output stage tube amplifier  DE  Loetstelle Very small footprint.  [In German. English here] 6EL84Audio Power AmpSingle Ended
    547HardAmp 1.0  DE  Loewenkatapult EL84 Stereo Amplifier  [In German. English here] 24ECC83,EL84Audio Power AmpSingle Ended
    548ECL 86 SE Verstarker  DE  Loewenkatapult Schematic and discussion, with pictures. ECL = 6WG8  [In German. English here] 12ECL86Audio Power AmpSingle Ended
    549Tone Amp Stage; HiFi, RCA  US  OPCOM's Julian Sienkewicz design. Schematic only. 2412AX7Audio Power AmpSingle Ended
    550PC Speaker Amplifier  US  OPCOM's This one gets the Strange Tube For This Use" award. 1670L7Audio Power AmpSingle Ended
    551211 Amplifier  NL  Mattij's Tube Schematic only. 166AU6, 12BH7, 211Audio Power AmpSingle Ended
    552Yet Another 2A3 Amplifier  NL  Mattij's Tube Schematic only. 112A6, 2A3Audio Power AmpSingle Ended
    553300B Amplifier  NL  Mattij's Tube Schematic only. 126SJ7, 300BAudio Power AmpSingle Ended
    55435A Amplifier  NL  Mattij's Tube Schematic only. 206J7, 35AAudio Power AmpSingle Ended
    5556550 Amplifier  NL  Mattij's Tube Schematic only. 216SN7, 6550Audio Power AmpSingle Ended
    5566AQ5 Amplifier  NL  Mattij's Tube Schematic only. 1312AT7, 6AQ5Audio Power AmpSingle Ended
    5576BX7 Amplifier  NL  Mattij's Tube Schematic only. The 6BX7's are in parallel 11ECC81, 6BX7Audio Power AmpSingle Ended
    5586V6 Amplifier  NL  Mattij's Tube Schematic only. 176J7, 6V6Audio Power AmpSingle Ended
    559VT52 Amplifier  NL  Mattij's Tube Schematic only. 12E83CC, VT52Audio Power AmpSingle Ended
    560Amity and Aurora  US  Nutshell HiFi Two Amplifiers with VERY extensive and perceptive comments 12ECC99, 300BAudio Power AmpSingle Ended
    561Free Lunch from Jeremy Epstein  US  Jeremy Epstein Extensive discussion of his thought process. Direct coupled. 126C45, 2A3Audio Power AmpSingle Ended
    562EL84 SE Hi Fi amplifier  DE  Radio Sammlung With negative feedback.  [In German. English here] 14ECC83, EL84Audio Power AmpSingle Ended
    563Single 6EM7 Amplifier  JP  RCImpact From Japanese. I think they meant single-ended.  [In Japanese. English here] 126EM7Audio Power AmpSingle Ended
    564Single 6L6 Amplifier  JP  RCImpact From Japanese. I think they meant single-ended.  [In Japanese. English here] 126L6Audio Power AmpSingle Ended
    565ECL 82 Ultralinear SE amplifier  DE  Roehrenkramladen Very compact and tidy.  [In German. English here] 19ECL82Audio Power AmpSingle Ended
    566A clock amplifier with the EL8  DE  Roehrenkramladen Approx. 1.75 Watts output  [In German. English here] 17EF6, EL8Audio Power AmpSingle Ended
    567ECL86 SE Amplifier  DE  Roehrenkramladen Several pictures of different peoples versions. 4 Watts total.  [In German. English here] 21ECL86Audio Power AmpSingle Ended
    568Amplifier / Phonkoffer  DE  Roehrenkramladen 2-stage amplifier for record player.  [In German. English here] 25ECC83, EL84Audio Power AmpSingle Ended
    569EL34 Single Ended Amplifier  DE  Roehrenkramladen Click Schaltbild" for schematic; "Bauteile" for parts list. 2x3 Watts.  [In German. English here] 206SN7, EL34Audio Power AmpSingle Ended
    5706 Watt SE EL34 Amplifier  DE  Roehrenkramladen Click Schaltbild" for schematic; "Bauteile" for parts list.  [In German. English here] 246SN7, EL34Audio Power AmpSingle Ended
    571SE with Grundig AT3 transducers; KT88 Endröhren and EF800  DE  Roehrensockel Scheamtic link is at bottom of page.  [In German. English here] 18KT1807, KT88Audio Power AmpSingle Ended
    572Minivollamps single end with EL34  DE  Roehrensockel No schematic; but the circuit is probably typicalMore important is the construction approach; which really seems doable.  [In German. English here] 1512AX7, 6V6Audio Power AmpSingle Ended
    573Parallel single end with single-aperture core output transformers  DE  Roehrensockel Cool looking; but I'm not sure I understand. 8 PL508 Endröhren and ECF80/E80F  [In German. English here] 23ECF80, ECC82, PL508Audio Power AmpSingle Ended
    5742-Stage Amp with PCL86  DE  Roehrensockel Another approach using tube similar to 6EM7 or 6BM8 (ie; driver and power in one dissimilar tube)  [In German. English here] 17PCL86Audio Power AmpSingle Ended
    575Stereo output stage single end AClet with PCL86  DE  Roehrensockel Very nice looking.  [In German. English here] 17PCL86Audio Power AmpSingle Ended
    57612AX7-6N6 Amplifier  US  Dave Schmarder One channel. Good, basic design. I've listed the tone control separately 1412AX7,6N6Audio Power AmpSingle Ended
    577300B Amplifier  JP  Single Ended Looks heavy. 23EF86,6CG7(2),300BAudio Power AmpSingle Ended
    5786550 Amplifier  JP  Single Ended Power tubes can be use EL34 ; KT88 ; 6L6GC instead of 6550" 1612AX7(2),6550Audio Power AmpSingle Ended
    5796AC5 Single Ended Amplifier  JP  Single Ended Not really sure I got the tubes right (or that it matters?) 126AC5(2),6CG7Audio Power AmpSingle Ended
    5802A3 Single Ended Amplifier  JP  Single Ended Those 2A3's can get expensive; though 196U8(2),2A3Audio Power AmpSingle Ended
    581EL84/6BQ5 SE Stereo Tube Amplifier  DE  Soldering Point Relatively common approach. Click on schematic to enlarge it.  [In German. English here] 20ECC82, EL84Audio Power AmpSingle Ended
    582EL84 SE 'Siamese' by R. LeGrand  NL  Tubes4All A small little amp; with astounding musicality"  [In Dutch. English here] 17ECC81,EL84Audio Power AmpSingle Ended
    583Kurt Steffensens Gorrilla Amps  US  T-Line Speakers Schematic only, with a couple of variations. 1[-]Audio Power AmpSingle Ended
    5845 Dollar 50EH5 Amplifier  US  T-Line Speakers Hey, this is what my first amplifier looked like! And the first sounds great. 950EH5Audio Power AmpSingle Ended
    585Guided Missle Amp  US  The Planet Made with Bendix military-grade hardened glass radar tubes or something like that. 106SL7, 6AR6Audio Power AmpSingle Ended
    586Morrison's Micro 3.5 Watt Amp  US  The Planet Schematic only. 116SL7, 2A3Audio Power AmpSingle Ended
    587Time Bandit SE 300B  US  Time Bandit Heavy metalwork is nice 165Z3, 300B, 6SN7, 300B, 6SN7 Audio Power AmpSingle Ended
    588Simple 45  US  Time Bandit Very basic SE amplifier, using 2A3 or 45 96SL7,45Audio Power AmpSingle Ended
    589Time Bandit SE 2A3  US  Time Bandit Update of his Simple 45 96SL7,2A3Audio Power AmpSingle Ended
    590Attilla: Single ended 300BXLS versterker  NL  Triode Dick In Dutch; I believe  [In Dutch. English here] 20D3a,27,300BXLSAudio Power AmpSingle Ended
    591Ceasar II Amplifier  NL  Triode Dick Monoblok single ended 300B verstarker. I like the typesetting of the schematic. Easy to read component values and voltages at key nodes.  [In Dutch. English here] 196N30P,300BAudio Power AmpSingle Ended
    592Cleo V: Voorversterker  NL  Triode Dick In Dutch; I believe  [In Dutch. English here] 19AZ1,D3a,ECC88Audio Power AmpSingle Ended
    593Goliath: Single ended 211 versterker  NL  Triode Dick In Dutch; I believe  [In Dutch. English here] 21D3a,27,211Audio Power AmpSingle Ended
    5946BQ5 Amplifier  US  Triode Store Schematic only. 25ECC81, 6BQ5Audio Power AmpSingle Ended
    5956BQ5 Autobias Amplifier  US  Triode Store Interesting approach to the bias 96BQ5Audio Power AmpSingle Ended
    596Simple 45 Amplifier  US  Triode Store Suggests 45 or 2A3 tubes. 96SL7, 45Audio Power AmpSingle Ended
    597KT88 Amplifier  US  Tube Builder Schematic only. 21EF86, KT88Audio Power AmpSingle Ended
    598833 Tube Amp  US  Tube Lab See the 833 version; it's a hoot: 195842, 833Audio Power AmpSingle Ended
    599Endstufe mit ECL82  DE  Tom Schlangen The URL was too long to enter into my listing.  [In German. English here] 28ECL82 (2)Audio Power AmpSingle Ended
    600Transformer Coupled Cathode Follower Driver Stage 6DRT - 300B SE  BE  SJS ElectroAcoustics Hurray for Belgium! (Sorry; this is the first site I've seen from there.) 176DRT, 300BAudio Power AmpSingle Ended
    6016J7 Driving a 300B Amplifier  CN  VT4C Sounds a menu item. I like it when a forum discusses a design. 176J7, 2A3Audio Power AmpSingle Ended
    6026J5 Single stage UTC A-25 Output  CN  VT4C In Chinese or English; Interesting main site. Can use 6J5 (which is 1/2 a 6SN7)  [In Chinese. English here] 56SN7Audio Power AmpSingle Ended
    603Solidarity from  NL  VT52 Good example of where getting matched tubes is critical 56p45Audio Power AmpSingle Ended
    604Thorium Power Amp from  NL  VT52 Experiment with Low Mu high power tubes 710Y, 842Audio Power AmpSingle Ended
    605VT52 Amplifier  NL  VT52 Author examines many different types of 45 tube; heaping praise all around 15RE134, VT52Audio Power AmpSingle Ended
    606Wardsweb Direct Coupled 2A3  US  Ward's Web Pretty slick for a first-timer 146SL7, 2A3Audio Power AmpSingle Ended
    607The Bugle Single 45 Amplifier  US  Wavelength Audio PDF File. From Sound Practices magazine 246072, 45Audio Power AmpSingle Ended
    608Two Tube Amplifier  US  Tom Kipgen's Schematic is on Dave Schmarder's site: 1412AX7,6N6Audio Power AmpSingle Ended
    6096EM7 amplifier  JP  Passionate Tube Ascii schematic.  [In Japanese. English here] 146EM7Audio Power AmpSingle Ended
    6106B4 SE Amplifier  JP  Passionate Tube Schematic only. What's with all the capacitors?  [In Japanese. English here] 335687, 6B4Audio Power AmpSingle Ended
    6116AQ5 Amplifier  JP  Passionate Tube Schematic Only.  [In Japanese. English here] 166AV6, 6AQ5Audio Power AmpSingle Ended
    612Audio Output Amplifier for Radios  JP  Portable From Japanese. The circuit uses a 6AB8, a triode/pentode that  [In Japanese. English here] 176AB8Audio Power AmpSingle Ended
    6132.5 Watt Amplifier  CR  B Zupan URL says “yell box”. What's that all about? Shiny transformers.  [In Croation. English here] 18EL84Audio Power AmpSingle Ended
    6142 Watt Amplifier  US  Audio Hobbyist Seems to be fairly simple construction 1312AX7, 6AQ5Audio Power AmpSingle Ended
    6156550 Single Ended Amplifier  SE  Zound Brigade Why these tubes? 1712DW7, 6550Audio Power AmpSingle Ended
    616Darling Amp (Swedish Cheap Shop)  SE  Zound Brigade Text says this was made with cheap parts. 118532, 1626Audio Power AmpSingle Ended
    61750CA10 Amplifier  SE  Zound Brigade Click through to schematic 1012AX7, 50CA10Audio Power AmpSingle Ended
    618807 STC SE Amp  SE  Zound Brigade Schematic says '807/1625' 146U8, 12AX7, 807Audio Power AmpSingle Ended
    619Captain PP Amp  US  DIY Paradiso Higher end. Nice picture of the crowd listening 236SL7, 6BL7, 845(2)Audio Power AmpSingle Ended
    620Simple SE Amplifier  IT  Research Triangle Not sure if this is really the simplest. 192A3Audio Power AmpSingle Ended
    6216C33C Single Ended Amp  ES  IGA Valves Schematic only. 286H1P, 6P3C, 6C33Audio Power AmpSingle Ended
    6226P3C / 6L6 Amp  ES  IGA Valves Schematic only. 286H1P, 6P3CAudio Power AmpSingle Ended
    623Mighty Midget Amp with Compactron  US  Pete Millet's Uses 6T10 so you only need one tube per channel 146T10Audio Power AmpSingle Ended
    6246BX7 Amplifier  JP  Electron Tube Index Minimal text with schematic  [In Japanese. English here] 1212AX7, 6BX7Audio Power AmpSingle Ended
    625Zodiac: Flea-Powered Amp for the Office  SE  Valvular Pages Schematic only. 12ECL82Audio Power AmpSingle Ended
    626Finale Single Ended 211/845  IT  Spazioinwind Schematic only.  [In Italian. English here] 10211/845Audio Power AmpSingle Ended
    6276C45-211 Amplifier Project  US  Lunarnet BBS Schematic and photos. Nice Looking. 116C45, 211Audio Power AmpSingle Ended
    628A Low Cost Valve Amplifier  UK  Nat'l Valve Museum from Practical Wireless, 1969 32EF86, ECL86Audio Power AmpSingle Ended
    629300B / 2A3 Single Ended Amplifier  JP  Shimosan That is, either 300B or 2A3, I believe  [In Japanese. English here] 186SN7, 300BAudio Power AmpSingle Ended
    6306L6 Single Ended Amp  JP  Shimosan In Japanese. Economical.  [In Japanese. English here] 1612AX7, 6L6Audio Power AmpSingle Ended
    631SV572-3 Single Ended Amplifier  JP  Sekido “Features Svetlana's new comer, SV572-3 . . . .Those really fascinated me because of its huge plate dissipation (125W !) and of beautiful plate linearity.” 276SL7, SV572-3Audio Power AmpSingle Ended
    632KISS Amp 300B  UK  Fi Ultra A full “course” on tube amp design for newcomers 206SN7, 300BAudio Power AmpSingle Ended
    63313EM7/15EA7 Single Ended Amplifier  US  Tom McNally's Amps 32nd project on this site! “This little amp sounds as good as my 2A3 amp and 300B amp !” 813EM7Audio Power AmpSingle Ended
    634SE Amp mit Russische Rohre 6S19-P (6C19)  DE  Jogis Roehrenbude “SE Amp with Russian Tube 6S19-P (6C19).”  [In German. English here] 326SH11, 6C19(2)Audio Power AmpSingle Ended
    635Der erste Mono - und der erste Stereo-Röhren-Verstärker   DE  Jogis Roehrenbude “The first mono and stereo tube amplifier”.  [In German. English here] 20EC92, EL95Audio Power AmpSingle Ended
    6366-Watt-HiFi-Röhren-Verstärker mit einer EL 84   DE  Jogis Roehrenbude “6-Watt Hifi Tube Amplifier with EL84”  [In German. English here] 24EF86, EL84Audio Power AmpSingle Ended
    637Daande Line Amp Project  DE  Suertenich Really interest parts fabrication pictures (tube sockets, attenuators, etc.) 2039-44, A409Audio Power AmpSingle Ended
    638T40 Triode Power Amps  DE  Suertenich Cool-looking output tubes, but where's the schematic? I can take a guess at the parts. 186EA7, 6EM7, T40Audio Power AmpSingle Ended
    639Eintakt-A-Röhren-Verstärker mit der 6C33C-B   DE  Jogis Roehrenbude “Single Ended Tube Amp with 6C33”. I don't understand this circuit at all.  [In German. English here] 286H8(2), 6C33Audio Power AmpSingle Ended
    640Stereoverstärker "6T9 SE" mit Compactrons   DE  Reinhard Stenzel “Stereo amplifier with 6T9 compactron”  [In German. English here] 176T9Audio Power AmpSingle Ended
    641Versaeker mit EF6 und EL8  DE  Frank Moller “Amplifier with EF6 and EL8”. Lots of really good pictures.  [In German. English here] 17EF6, EL8Audio Power AmpSingle Ended
    642Versaeker mit EC92, EL95  DE  Frank Moller “Amplifier with EC92 and EL95”. Lots of really good pictures.  [In German. English here] 17EC92, EL95Audio Power AmpSingle Ended
    643Der Buchen-Amp: quadratisch-praktisch-gut!   DE  Jogis Roehrenbude “The Book Amp: Square is Good”.  [In German. English here] 21ECC83, EL84(2)Audio Power AmpSingle Ended
    644Das Neue Projekte  DE  Frank Moller “The New Project”. Would this work? Only 3 parts.  [In German. English here] 3TriodeAudio Power AmpSingle Ended
    645Einfacher Kopfhörer-Verstärker   DE  Erinacom “Simple Headphone Amplifier”  [In German. English here] 9ECC82Audio Power AmpSingle Ended
    646Trioden – Amp mit 4 Röhren 6EM7   DE  Jogis Roehrenbude “Triode Amp with 4 6EM7 Tubes”. Parallelling the tubes in the typical circuit.  [In German. English here] 236EM7(4)Audio Power AmpSingle Ended
    647Strategos RS 282 Monoblöcke mit den Wehrmachtsröhren RS282   DE  Jogis Roehrenbude “Strategos RS-282 Monoblock With Wehrmacht Tube RS282”. Those are some scary-looking tubes.  [In German. English here] 21LD1, RL12P10, RS282Audio Power AmpSingle Ended
    648Melomania VT-4-C / 211   DE  Jogis Roehrenbude Serious blue glow in the tubes. Very sturdy construction / lots of pictures.  [In German. English here] 216SN7, 211Audio Power AmpSingle Ended
    6491626 SE Amp  DE  Jogis Roehrenbude Note the picture of the breadboard mock-up. I've been there lots.  [In German. English here] 12ECC83, 1626Audio Power AmpSingle Ended
    650EL84 Amp im Epoxidharz Gehause  DE  Jogis Roehrenbude EL84 Amp in Epoxi Housing”. (I think). Beautiful picture of tubes in full glow.  [In German. English here] 14EL84, EM84Audio Power AmpSingle Ended
    651Vorverstärker mit niederohmigem Ausgang   DE  Jogis Roehrenbude Appears to be maybe a preamplifier with power stage?  [In German. English here] 126SJ7, 6V6Audio Power AmpSingle Ended
    652Trion 34 MarkII  DE  Jogis Roehrenbude Described as a “purist's” single ended tube amplifier  [In German. English here] 126SN7, EL34Audio Power AmpSingle Ended
    653The Small ECL86 Amplifier  DE  Jogis Roehrenbude Cute looking  [In German. English here] 14ECL86Audio Power AmpSingle Ended
    654EL36 Triode Amp  DE  Jogis Roehrenbude Small footprint.  [In German. English here] 246SN7, EL36(2)Audio Power AmpSingle Ended
    655EF95 und 6Sh1P als NF-Verstärker   DE  Michael Gaedtke “EF95 and 6SH1P as Audio Amplifier”.  [In German. English here] 426SH1P(2), 6N3P(2)Audio Power AmpSingle Ended
    656HybridVerstaerker Mit 6N3P  DE  Michael Gaedtke “Hybrid Amplifier with 6N3P”. Has a MOSFET-based current amplifier.  [In German. English here] 266N3PAudio Power AmpSingle Ended
    657PCL86 Stereoversaerker  DE  Roehrenbastler “PCL86 Stereo Amplifier” Nice blue glow; see pictures  [In German. English here] 20PCL86Audio Power AmpSingle Ended
    658Funf Minuten Verstaerker  DE  Roehrenbastler “Five Minute Amplifier”. Just point-to-point soldering; no chassis, no sockets, etc. Radios used to be done like this all the time. How about this approach, with, say, a 6EM7?  [In German. English here] 13ECC81, EL34Audio Power AmpSingle Ended
    6593-Watt EL34 Versaerkerna  Tube Amp “3-Watt EL34 Amplifier”.  [In German. English here] 226SN7, EL34Audio Power AmpSingle Ended
    6604-Watt 6CA7 Vestaerkerna  Tube Amp “4-Watt 6CA7 Amplifier”. Nice meters on the front.  [In German. English here] 2212AX7, 6CA7Audio Power AmpSingle Ended
    6611.5-Watt ECL82 SEVestaerkerna  Tube Amp “1.5-Watt ECL82 Amplifier”.  [In German. English here] 18ECL82Audio Power AmpSingle Ended
    6626EM7 SE Amplifier  MY  Audio Hobbyist Interesting circuit board mounting 126EM7Audio Power AmpSingle Ended
    6635W Tube Power Amplifier with EL84na  Sam's Circuits Interesting switch allows user to switch between 'triode' strapping on EL84, or 'pentode'  [In Greek. English here] 1912AX7, EL84Audio Power AmpSingle Ended
    6643W Amplifier  US  Photobucket One tube (6BM8) for both stages. 126BM8Audio Power AmpSingle Ended
    665EL84 Amplifier  US  Photobucket Schematic only. 1312AX7, EL84Audio Power AmpSingle Ended
    666JDPP Amp – Great WMV!  NL  BasAudio There should be more of this: an 8MB video with several great clips, a tour of the project, the schematic, etc. 12[-]Audio Power AmpSingle Ended
    667845 SE Amplifier  FR  Magnetic Free Not sure if I got those tubes right. Also; the translation engine was having trouble with the French on the commentary page.  [In French. English here] 23ECC83,EL93,845Audio Power AmpSingle Ended
    6682A3 single ended power amplifier  DE  IK Schiffer Translated from the German.  [In German. English here] 14E80CC,2A3Audio Power AmpSingle Ended
    669J.C. Morrison Circuit - Amplifier  DE  IK Schiffer Minimal parts.  [In German. English here] 106SL7, 2A#Audio Power AmpSingle Ended
    670SE Amp with 6141c  DE  Basenjes Look at the photo at the bottom of the page; I think the approach is striking. 146141cAudio Power AmpSingle Ended
    671Kismet Amplifier  DE  IK Schiffer From a German site. Main page is  [In German. English here] 126922,2A3Audio Power AmpSingle Ended
    672Loftin and White 2A# SE Amp  DE  IK Schiffer Minimal parts for 2A6 and 2A3.  [In German. English here] 112A6, 2A3Audio Power AmpSingle Ended
    673El Spuddo SE Amp  DE  Basenjes Looks like a good quick project; not sure I've seen those tubes around much 126545PAudio Power AmpSingle Ended
    674EL84 Single Ended Amplifier  JP  Lagarto Japanese builder; but page is in English  [In Japanese. English here] 146AQ8,EL84Audio Power AmpSingle Ended
    675Simple 45 / 2A3  JP  JE Labs Another take on a classic design from the RCA tube R-C amp chart" 146SL7, 45Audio Power AmpSingle Ended
    676Single Ended Tube Power Amplifier  US  Gabe's Tube Amps Very throughout account of what he went through 226SL7,6L6Audio Power AmpSingle Ended
    677Half-Watt transformer-coupled 6EM7 amp  US  Rutgers Music I greatly appreciated the history lesson and how it applied to the 6EM7. I also notice he used a filament transformer as an output transformer for this tube (which I've done before). 126EM7Audio Power AmpSingle Ended
    6786BM8 Ampna  Bunny's Projects The translation is interesting.  [In Korean. English here] 136AK5, 6BM8Audio Power AmpSingle Ended
    679Simple Valve Amplifier with KT-88  FR  M Terrier KT-88 = 6550  [In French. English here] 20ECC808, KT88Audio Power AmpSingle Ended
    680Single ended 6s4 amplifier with a 6dj8 SRPP driver stage  US  Boozhound Labs Similar to the 6S4 Micro Triode Amp 146DJ8, 6S4Audio Power AmpSingle Ended
    68110 Watt Stereo Amplifier using ECCL800 Tube  FR  M Terrier Tube name in schematic is apparently a typo.  [In French. English here] 326KH8Audio Power AmpSingle Ended
    682True Triode Amplifier with 300B  FR  M Terrier Lot of colors and fonts on this page; that's for sure.  [In French. English here] 306BM8, 300BAudio Power AmpSingle Ended
    683AMPLI KT88 Psuedo Triode  FR  M Terrier Several variations on this page.  [In French. English here] 25ECL82, KT88Audio Power AmpSingle Ended
    684Simple Stereo Amplifier with EL34  FR  M Terrier Project for engineering students; note the comparison with the Professor's model (further down the page)  [In French. English here] 20ECC88, EL34Audio Power AmpSingle Ended
    6856V6 Hi Fi Amplifier  US  Boozhound Labs The schematic is from; which I believe is a Korean site - how cool is that?" 136SL7,6V6Audio Power AmpSingle Ended
    6866EA7 Amplifier  JP  Simplicity Audio No schematic here; but the pictures are nice. See some of the 6EM7 amps for a circuit.  [In Japanese. English here] 156EM7Audio Power AmpSingle Ended
    687211 SE Amp - from tutorial  US  Fi Primer See the text discussion at 196SN7 (2), 211Audio Power AmpSingle Ended
    6882A3 SE Amp - from tutorial  US  Fi Primer See the text discussion at 146SL7, 2A3Audio Power AmpSingle Ended
    689300B SE Amp - from tutorial  US  Fi Primer See the text discussion at 156SN7, 300BAudio Power AmpSingle Ended
    6906L6 SE Amp - from tutorial  US  Fi Primer See the text discussion at 16EF86, 6L6Audio Power AmpSingle Ended
    691Audio amplifier with ECL80  SL  B Zupan The stereo version further down the page is an interesting variant.  [In Slovenian. English here] 9ECL80Audio Power AmpSingle Ended
    692Audio amplifier with EL84  SL  B Zupan I'm guessing at the language here.  [In Slovenian. English here] 10ECC83, EL84Audio Power AmpSingle Ended
    693Amplifier with PL504  SL  B Zupan [From Slovenian?]  [In Slovenian. English here] 12PL504Audio Power AmpSingle Ended
    69450C5 Single Ended Triode Amplifier  US  T Williams Uses the tubes from the All American Five. Radios and Amps Unite! 1714GT8, 50C5Audio Power AmpSingle Ended
    6956L6GC SE Amplifier  US  T Williams Interesting optional tone control; and comments on the inclusion of a Zobel network 3412AX7, 6L6GTAudio Power AmpSingle Ended
    696JE Labs 300B SE Amp  US  Angela Instruments I am merely a 'triode chef' mixing a concoction of ingredients" 166SN7, 300BAudio Power AmpSingle Ended
    697JE Labs Stereo Single Ended 2A3 Amplifier  US  Angela Instruments 2001 Edition. Good discussion of parts. 146SL7, 2A3Audio Power AmpSingle Ended
    698Stereo SE EL34 HiFi Amplifier  US  Angela Instruments From Angela Instruments 136SL7, EL34Audio Power AmpSingle Ended
    6995-Watt Amp for 6T10 Compactron  US  Beans Amps Schematic only. Notice the FET 266T10Audio Power AmpSingle Ended
    700Simple Amp with 6AU6; 6BQ5  US  Beans Amps Schematic only. 126AU6, 6AB5Audio Power AmpSingle Ended
    701Audio Amplifier for Compactron Tubes  US  Wade's Audio Discussion of background 2012AE10Audio Power AmpSingle Ended
    702Single Ended 6BQ5 Amplifier  US  Wade's Audio Built on a Zenith base. 1212AX7, 6BQ5Audio Power AmpSingle Ended
    703845 SE Mono Power Amplifierna  Nuance and Fluence From Turkey. Article in Sournd Practices magazine. 306072A,300B,845Audio Power AmpSingle Ended
    704Nuance: 845 SE Mono Power Amplifierna  Nuance and Fluence From Sound Practices"; I think 296072a,300B,845Audio Power AmpSingle Ended
    705Parallel Single Ended Amplifier  IT  Paeng Design More variations on a theme  [In Italian. English here] 86C45Audio Power AmpSingle Ended
    706Single Ended Amplifier  IT  Paeng Design Schematic; parts list; and some results.  [In Italian. English here] 76C45Audio Power AmpSingle Ended
    707Duct cells (1U4 - 3S4) Amplifier  JP  Vacuum Tube Radio From Japanese. Looks like another kit. Why can't we get these in the US? 0.12W per channel output  [In Japanese. English here] 101U4,3S5Audio Power AmpSingle Ended
    708Single Ended Dual Mono Amplifier  IT  Paeng Design Not sure of the point here.  [In Italian. English here] 76C45Audio Power AmpSingle Ended
    709SV572-3 Single Ended Amplifier  IT  Audio Design Guide It's always heartening when they say This project can kill you!" 136SN7,6BX7,SV572-3Audio Power AmpSingle Ended
    710The new 300BXLS Single Ended Amplifier  IT  Audio Design Guide From Italy. Quite impressive; even in the prototype stage  [In Italian. English here] 226EM7, 300BAudio Power AmpSingle Ended
    711SETA - Single Ended Tube Amplifier  IT  Audio Design Guide From Andrea Ciuffoli. Check out his extensive projects page. 176SN7, KT90Audio Power AmpSingle Ended
    7126AS7 SE Amplifier  MY  Audio Hobbyist Looks like a good beginner project 1412AU7,6AS7Audio Power AmpSingle Ended
    7136EM7 SE Amplifier  MY  Audio Hobbyist Look at picture to see a triumph of compact thinking. 156EM7Audio Power AmpSingle Ended
    7146EW7 SE Amplifier  MY  Audio Hobbyist Lots of pictures of this nice-looking kit (apparently cheap; too; when not sold out). 146EW7Audio Power AmpSingle Ended
    7153 Watt EL34 SE-AMP  DE  Musik Ding Interesting construction material  [In German. English here] 5EL34Audio Power AmpSingle Ended
    7166P3P Single Ended Amplifier  MY  Audio Hobbyist Nice stereo setup. This might be a good first-time project. 1712AT7,6P3PAudio Power AmpSingle Ended
    717WE-717A + 2A3 SE amplifier  MY  Audio Hobbyist Pretty transformers 12WE717A,2A3Audio Power AmpSingle Ended
    718Output Transformerless (OTL) Ampna  Audioton I like the schematic design.  [In Polish. English here] 20ECL86Audio Power AmpSingle Ended
    7192A3 Simple Ampna  Audiovn Club Scroll down to post #100  [In Vietnamese. English here] 1712AT7, 2A3Audio Power AmpSingle Ended
    720Russian Language Amplifier Schematicna  Audiovn Club Scroll half way down page. Schematic is next to the picture of Kurt Cobain  [In Vietnamese. English here] 206SH32, 6H1P, GM70Audio Power AmpSingle Ended
    721Another 6AS7 Amplifierna  Audiovn Club Scroll 60% of way down page to Post #33.  [In Vietnamese. English here] 166DJ8, 6AS7Audio Power AmpSingle Ended
    7226AS7 Amplifierna  Audiovn Club Scroll 60% of way down page to Post #31.  [In Vietnamese. English here] 236BM8, 6AS7Audio Power AmpSingle Ended
    7236L6 Amplifierna  Audiovn Club Scroll half way down.  [In Vietnamese. English here] 20ECC81, 6L6Audio Power AmpSingle Ended
    7242A3 SE Amplifierna  Bonavolta Schematic only. 2A6 is driver. 92A6, 2A3Audio Power AmpSingle Ended
    7256L6 SE Ampna  Bonavolta Schematic only. 3 Watts 20ECC81, 6L6Audio Power AmpSingle Ended
    7266V6 SE #1 Ampna  Bonavolta Schematic only. From 1949. SE cathode follower. 106SJ7, 6V6Audio Power AmpSingle Ended
    7276V6 SE #2 Ampna  Bonavolta Schematic only. From 1957. 4.2 watts. Used as a treble amplifier. 156J7, 6V6Audio Power AmpSingle Ended
    728VT 52 Single-Ended SRPPna  Bonavolta Inlcudes PCB; photos; oscilloscope output; etc. 17ECC83, VT52Audio Power AmpSingle Ended
    729VT-52 SE Amplifier #2na  Bonavolta Schematic only. Uses 1/2 E83CC. 12E83CC, VT52Audio Power AmpSingle Ended
    730VT-52 SE Amplifier #3na  Bonavolta Schematic only. The ECC83's are in parallel. 14E83CC, VT52Audio Power AmpSingle Ended
    73115W SE Power Amplifier with Two-Stage Driver.  US  Borbely Audio From a Danish site (I think). Interesting things on this site; including kits. 346SN7, 6J5, 6C33Audio Power AmpSingle Ended
    732Single Ended eXperimenter's kit  US  Bottlehead Uses the 6DN7 dissimilar triode so you have both driver and power amp in same section. 156EM7Audio Power AmpSingle Ended
    733Audio Amplifier with transistor  NL  Radio Morningstar Schematic Only.  [In Dutch. English here] 2312AX7, 6V6Audio Power AmpSingle-Ended
    7346SN7WGTA single compact stereo power amplifier  JP  Satoshi's Home Page Apparently this was tried with different tubes. I think. Note the picture of the runaway tube in the darkness.  [In Japanese. English here] 106SL7,6SN7Audio Power AmpSingle-Ended
    7356EM7 Small Bedroom Amplifier  JP  Satoshi's Home Page I've built one of these, but got different voltages. I wonder why.  [In Japanese. English here] 106EM7Audio Power AmpSingle-Ended
    73671A Classic Tube Amplifier  JP  Satoshi's Home Page Pictures of different potential layouts  [In Japanese. English here] 126267,71AAudio Power AmpSingle-Ended
    737EL34 Single Ended Amplifier  JP  Satoshi's Home Page Great pictures, and very helpful oscilloscope output.  [In Japanese. English here] 116DL4,EL34Audio Power AmpSingle-Ended
    7381626 (VT-137) compact SHINGURUSUTEREOPAWAANPU  JP  Satoshi's Home Page Babelfish breakdown. Audio Amplifier  [In Japanese. English here] 116DJ8,1626Audio Power AmpSingle-Ended
    739VT-25 Amplifier  JP  Satoshi's Home Page Again, lots of placement experiment pictures  [In Japanese. English here] 126267,6922,VT-25Audio Power AmpSingle-Ended
    740Universal Amplifier to Test 211/VT-4C Type Tubes  JP  Shoranosekai Interesting set-up allows playing with tubes and; it appears; capacitors  [In Japanese. English here] 2012AX7Audio Power AmpTest Bed
    741Universal Amplifier to Test Popular Triodes  JP  Shoranosekai Interesting set-up allows playing with tubes and; it appears; capacitors  [In Japanese. English here] 2012AU7Audio Power AmpTest Bed
    742Gegentaktverstärker mit vier EL95  DE  Elektronic Bastelbude Off-beat (?) Amplifier with EL95  [In German. English here] 9EL95 (2)Audio Power AmpX
    743Darling Amplifier With Lots of Examples  MY  DIY Paradise What a Great Page! Dozens of versions of a simple design! 105965,1626Audio Power AmpX
    7445965/2A3 Amplifier byh Stephen Chenna  DIY song VERY Detailed construction photos. From the incredible linklist  [In Chinese. English here] 145965,2A3Audio Power AmpX
    7456AQ5 Amplifier  CN  DIY song In Chinese (I think)  [In Chinese. English here] 1512AT7,6AQ5Audio Power AmpX
    7466C45Pi Amplifier  CN  DIY song As good-looking as they come  [In Chinese. English here] 96C45,6C41Audio Power AmpX
    747Li'l 4x4 Tube Amplifier  DK  Fred Nachbaur Classic push-pull 35C5 design 2612AX7, 35C5(2)Audio Power AmpX
    748EXPERIMENTS WITH PARAPHASE SPLITTERS (A Vacuum Tube Multimedia Amplifier)  DK  Fred Nachbaur Can use 6X8A's; which I seem to have a lot of. 1912AX7 (2), 6AQ5 (2)Audio Power AmpX
    749Audioverstärker mit der PCL86  DE  Elektronik-Bastelbude Audio Amplifier with the PCL86"  [In German. English here] 21PCL86Audio Power AmpX
    750Zweistufiger NF-Verstärker  DE  Elexs Two-layered Amplifier"  [In German. English here] 10EF95Audio Power AmpX
    7516BM8 super 3 amplifier  JP  Technopolis Include a FET. Page is translated from the Japanese; and some didn't convert.  [In Japanese. English here] 166BM8Audio Power AmpX
    7526CL6 super 3 amplifier  JP  Technopolis Include a FET. Page is translated from the Japanese; and some didn't convert.  [In Japanese. English here] 1812AT7,6CL6Audio Power AmpX
    753Dave Ewing's 300B Integrated stereo Amp  DE  K4DE Nice looking. 50 Watts.  [In German. English here] 306SL7,6SN7(2),6AG7,300BAudio Power AmpX
    754Dave Ewing's 300B Integrated stereo amp  US  K4DE Note the table it's on: a candlestick and a quill pen! It evokes that 1800's; world lit only by fire and a 300B" feeling. 326SL7,6SN7(2),6AG7,300BAudio Power AmpX
    755*ANGELO* A simple two stage Amplifier  IT  Research Triangle He talks about some issues with 2 stage amps (driver and final)  [In Italian. English here] 146C45P,2A3Audio Power AmpX
    756Francesca 2000 - a 572-3 DHT Amplifier  IT  Research Triangle “The best discovery I've recently made is the new 6c45 Tube. This little monster si able to dissipate 8w; has insignificant noise and 900ohm Rp (!)."  [In Italian. English here] 206C45,2A3,572-3Audio Power AmpX
    75750EH5 Amplifier  JP  Dad's Projects Chassis is an ashtray. And these heavy filaments essentially substitute for a power transformer  [In Japanese. English here] 650EH5Audio Power AmpX
    7586AQ5 Amplifier  US  Headwize Preamp and power stage 1512AX7,6AQ5Audio Power AmpX
    759Big Tube Amp  US  Sparkgap Now; that's a BEAST! I like the original approach to construction. 14437A,300BAudio Power AmpX
    7606B4G Integrated Mono  RU  Klausmobile Um; where is te 6B4G?  [In Russian. English here] 146C45,6C4CAudio Power AmpX
    761Dual Triode Stereo Amplifier  US  Lighthouse Electric Schematic only; but seems simple enough. 2212AX7Audio Power AmpX
    762STA-45 Stereo Amplifier  US  Lighthouse Electric Looks like a kit; but they let you see the schematic as well as a photo 2212AU7,6BQ8Audio Power AmpX
    763N3P Amplifier  DE  Michael Gaedtke The Ñ3P is the Russian equivalent of the American 2C51 and 5670 - a double triode with middle slope and relatively high acceptable current load". Translated from the German.  [In German. English here] 18N3P(2)Audio Power AmpX
    764EF95 and 6Sh1P as NF amplifiers  DE  Michael Gaedtke I've got to learn those Russian tube numbering systems  [In German. English here] 146Sh1PAudio Power AmpX
    765Islander Construction Audio Amplifier  US  NJ QRP This construction technique is neat" 20[-]Audio Power AmpX
    766HIFi Power Amplifier  IT  Radio Pistoia English and Italian versions of page available. Design is from an Italian magazine called Nuova Elettronica.  [In Italian. English here] 21ECC82,KT88Audio Power AmpX
    767845 20W A1 class monotriode amplifier  FR  Triode Audio Two other projects lower on the page  [In French. English here] 256SL7,300B,845Audio Power AmpX
    768Pure Class A Amplifier  FR  Triode Audio Is a photo working?  [In French. English here] 22EF86,EL34,845Audio Power AmpX
    769Croft Series 5 valve power amplifier  UK  Alex's Page Funny comment on the power arrangement 34ECC83(2),EL84(4)Audio Power AmpX
    770833 Ultra ParaFeed by R. de Vries  NL  Tubes4All Check out the factory floor". They said it took a week to construct these.  [In Dutch. English here] 196SN7(2),300B(2)Audio Power AmpX
    77145 46 300B Convertible Triode Amp  US  The Planet Read the attached article on the Bugle amplifier from which this design is taken. 405751(2),45(2)Audio Power AmpX
    772RH 807 SE  US  Tube Audio Single Ended Amp with some discussion 15ECC81,807Audio Power AmpX
    7736BM8 Amplifier  AU  Cool 386 Schematic Only. 106BM8Audio Power AmpX
    774EC88 RC 2A3 Dual-Mono Intergated AMP  CN  VT4C In Chinese or English; Interesting main site  [In Chinese. English here] 13EC88,2A3Audio Power AmpX
    775Simple Power Amplifier  CN  VT4C In Chinese or English; Interesting main site  [In Chinese. English here] 156C45PI,845Audio Power AmpX
    776Five Tube Stereo Amplifier  US  W Kinsler 4 watts output max. per channel; 8 watts bridged 196FS5,6K6Audio Power AmpX
    777D. T. N. Williamson tube amplifier  NL  van der Kerk Very extensive (10 pages) discussion of a classic circuit and the implications of its design ideas. 336SN7(3),KT88(2)Audio Power AmpX
    778The most complete do it yourself guide on the D. T. N. Williamson tube amplifier  NL  van der Kerk Dissection of a classic tube-based audio amplifier 346SN7 (2),KT66 (2)Audio Power AmpX
    77912GB7 Amplifier (Main page:  JP  Maizuru Translated from the Japanese  [In Japanese. English here] 1212AX7,12GB7Audio Power AmpX
    7802A3 Loftin-White  JP  Maizuru Translated from the Japanese  [In Japanese. English here] 1412AX7,2A3Audio Power AmpX
    7816AQ5 BSD Amplifier  JP  Maizuru I've been meaning to look up the meaning of BSD in this context  [In Japanese. English here] 1612AX7,6FQ7,6AQ5Audio Power AmpX
    782UZ42 Amplifier  JP  Maizuru Translated from the Japanese  [In Japanese. English here] 1612AX7,6FQ7,42Audio Power AmpX
    783HI-FI Audio Amp Using Only 3V  US  Sparkbench I'm not sure I understand this circuit; 50-100 MW 71S4Audio Power AmpX
    7845W Audio Amplifier  US  Sparkbench See /sbench101 main site for discussion link 291U4 (3),6AK6 (2)Audio Power AmpX
    785Single Tube audiophile amplifier  US  Glow Bug Kits This is for a single channel. 15ECL82Audio Power AmpX
    7866EM7 DC Coupled Triode Amp  US  The Planet Can the parts count get much smaller? Run direct off a CD. 96EM7Audio Power AmpX
    7876S4 Micro Triode Amp  US  The Planet 1.25 Watts output. 156N1P (2), 6S4AAudio Power AmpX
    788Mullard 3-Valve 3-Watt Amplifier  UK  Vintage Radio Mid-50's standard design; apparently. Change 1" at end of URL to 2; 3; 4; 5; 6 for other pages 18EF86, EL84Audio Power AmpX
    7896BM8 Line Operated Amp  US  T Williams Schematic Only 256BF6, 6BM8Audio Power AmpX
    7906AN8 & EL84/6BQ5 Project Amplifier  AU  Cambie An experiment using a line transformer as an output transformer 386AN8,6BQ5(2)Audio Power AmpX
    7916CM5 / EL36: Applications in Audio  AU  Cambie Not sure about that middle tube. 3512AX7,5965(?),6CM5Audio Power AmpX
    792ECL80 Amplifier  DE  Andreas Kirschner What is a Verbundröhre"?  [In German. English here] 14ECL80Audio Power AmpX
    793THE RADIO NEWS 1940 FULL-RANGE AMPLIFIER  US  Antique Radio Looks way over-engineered to me. 606L7,6C5,6H6,6A3(2)Audio Power AmpX
    7941626 DARLING  MY  Audio Hobbyist 0.7 watts of output power. 126N1P,1626Audio Power AmpX
    7956SN7-2A3 power amplifier  MY  Audio Hobbyist The underside is as pretty as the top. 146SN7,2A3Audio Power AmpX
    796Class A Amplifier; 5-7 Watts  DE  Musik Ding This is an AX84 P1. See  [In German. English here] 30EL34Audio Power AmpX
    797Designing an Amplifier: Feedback Amplifier  US  Audio Xpress Detailed design approach; charts; formulas; etc. 2412AX7, 12AU7, 6L6(2)Audio Power AmpX
    798Röhren-Verstärker mit der ECC86  DE  B Kainka Tube Amplifier With the ECC86"  [In German. English here] 12ECC86Audio Power AmpX
    799Stereo-Power mit Röhren  DE  B Kainka Stereo Power with Tubes". Cool looking tubes.  [In German. English here] 9SRS326 (2)Audio Power AmpX
    800Stereo-Verstärker; vier mal PL504  DE  B Kainka Stereo Amplifier" With four more PL504  [In German. English here] 8PL504 (4)Audio Power AmpX
    801Alfred P. Morgan 3-Tube Audio Amplifier  US  Big Nick's Basic two-stage audio amplifier 1212SQ7,35Z5,50C6Audio Power AmpX
    802Preamplifier  NL  Radio Morningstar Schematic Only.  [In Dutch. English here] 2012AX7Audio Preamplifier2-Stage
    803Choke-Loaded 26 Tube Preamplifier  NL  VT52 This is the best damned preamp I've ever built." Initially this involved more hum battling; A great learning experience here 826Audio PreamplifierChoke-Loaded
    804Choke-loaded preamp with 10Y  NL  VT52 Same as his 26 tube version; with a different tube and power supply 910YAudio PreamplifierChoke-Loaded
    805The Baxandall preamplifier  DE  Christian Julius Project is towards the end of the page.  [In German. English here] 23ECC82Audio PreamplifierLine Amp
    806Differential line pre- amplifier  JP  Passionate Tube This has got to win the prize for most obscure schematic font.  [In Japanese. English here] 1212AX7Audio PreamplifierLine Amp
    807Tube Line Amplifier Project #1na  Sam's Circuits Some commentary, schematics, parts, power supply, etc. 26ECC82, ECC81Audio PreamplifierLine Amp
    808RadioHead Tube Preamp  US  DIY Guitarist Apparently designed by Gringo" in Argentina 1712BA6, 12AT7Audio PreamplifierLine Preamp
    809Grounded Grid Amplifier  MY  DIY Paradise I didn't know you could tune" a choke a noise type. He makes a pitch for using plate chokes ("supplies instantaneous power for transients"); and later notes that with 6688 tubes; "everything is better". 85842Audio PreamplifierLine Preamp
    810Linestage Preamp  BR  DeDe's Repository Note the time-delay circuit and his explanation of why it's there. 2612AX7, 12AU7Audio PreamplifierLine Preamp
    811Low parts count 6SN7 Preamp  US  Tube Builder Schematic only. 96SN7Audio PreamplifierLine Preamp
    8126DJ8 Line Amplifier  US  Tube Builder Schematic only. 326DJ8 (2)Audio PreamplifierLine Preamp
    813Line Preamplifier  JP  Passionate Tube ASCII schematic is hard to read.  [In Japanese. English here] 1012AX7Audio PreamplifierLine Preamp
    8146SN7 Tube Preamplifier  FR  Baligant Very detailed and interesting schematic. I'll need to spend some time; though; figuring out what all is going on here.  [In French. English here] 286SN7 (4)Audio PreamplifierLine Preamp
    815LineAmp by New York Dave  US  Electronic Dave Some discussion in the forum at (40% of the way down.) 2512AV7 (2), 12BH7 (2)Audio PreamplifierLine Preamp
    8165687 Line Preampna  Bonavolta Schematic only. 85687Audio PreamplifierLine Preamp
    817Counterpoint Preamp  DE  AlexTubes I can't find a schematic, but the beautiful pictures and unusual parts layout are worth tracking down the circuit  [In German. English here] 30ECC83Audio PreamplifierLine
    818Daniel Preamp  DE  AlexTubes Notice the flat construction. Lots of close pictures of unusual parts placement  [In German. English here] 30ECC88(2)Audio PreamplifierLine
    819Microphone Preamplifier  BR  DeDe's Repository From Croatia; I think. 2312AX7 (2)Audio PreamplifierMic Preamp
    820Tube Mic Preamp  US  Prodigy-Pro At least I think it was intended for a mic 166SN7 (2)Audio PreamplifierMic Preamp
    8216EM7 Microphone Preamp  US  Prodigy-Pro I like the discussion in this type of forum of Why did you do X in your design?" 166EM7Audio PreamplifierMic Preamp
    8226EM7 Mic preamp  US  Prodigy-Pro 6EM7 is an old favorite of mine. Lots of circuit discussion in this forum. 156EM7Audio PreamplifierMic Preamp
    823Mic Preamp; V76 sort of?  US  Prodigy-Pro From Prodigy-Pro Forum 23EF804, E83FAudio PreamplifierMic Preamp
    824Mu Stage Tube Mic Preamp  US  Vuotto Lots of abbreviations in that title. Yes; a MOSFET snuck in there. And the tube is apparently flexible. 2212AU7Audio PreamplifierMic Preamp
    825Condensator Microphone Preamplifier  NL  Mattij's Tube Schematic. In Dutch, I think.  [In Dutch. English here] 16ECC83Audio PreamplifierMicrophone Preamp
    826Hampton Tube Preamplifier for Moving Coil Pickupna  Sam's Circuits The power supply lower on the page is more complicated than the preamp.  [In Greek. English here] 18ECC88Audio PreamplifierMoving Coil Pickup
    827Mu-stage preamp- and headphone amplifier  NL  DHT Rob His motivation: I wondered what the difference would be in listening to an electrolytic capacitor in stead of an output transformer."  [In Dutch. English here] 166688,27Audio PreamplifierMu-Stage
    828Nuvistor Preamp  DE  AlexTubes Cute little capsules. I'll bet this isn't done often. His collection box is to drool over.  [In German. English here] 18NuvistorAudio PreamplifierNuvistor
    829Pencil-Tube Preamp  DE  AlexTubes I like pencil tubes.  [In German. English here] 226021(2),6111Audio PreamplifierPencil Tube
    830Phono Preamp  JP  JE Labs Schematic only 166SL7Audio PreamplifierPhono Preamp
    831Phono RIAA Preamplifier  US  Tobi's Homepage Nice workspace. 33ECC81Audio PreamplifierPhono
    83212B4-based linestage preamp  MY  DIY Paradise DIYParadise is a fun site to read. For some reason; I have of lot of these tubes. 812B4Audio PreamplifierPreamplifier
    833Simple 5687-based preamp  MY  DIY Paradise Serious audio site recommends this as a first DIY project 75687Audio PreamplifierPreamplifier
    834Two Tube Preamplifier  US  Bob Danielak One Channel 1712SL7, 12SN7Audio PreamplifierPreamplifier
    835Phono Preamp  US  Bob D His motivation was something to listen to Velvet Underground on. 1712SL7,12SN7Audio PreamplifierPreamplifier
    836Klauskorrektor I: First phono stage  RU  Klausmobile In English; from a Russian site.  [In Russian. English here] 256S4PEV,6F12Audio PreamplifierPreamplifier
    837STA1 Three Stage Stereo Pre-Amp with Tone Controls  US  Lighthouse Electric A classic RC coupled amplifier. Overall gain of the preamp is 60. 3612AX7,12AU7Audio PreamplifierPreamplifier
    838Tube Preamp (Bitches Brew in a Bottle)  US  Semfielec I like the granite faceplate. Looks solid. 246922(2)Audio PreamplifierPreamplifier
    839Croft Super Micro Preamplifier  UK  Alex's Page There are a couple of evolutions here. 29ECC83,ECC82Audio PreamplifierPreamplifier
    840The Search for the Perfect Linestage  US  The Planet From Garys Tube Page 106SN7Audio PreamplifierPreamplifier
    841Simple Pre-Amplifier  CN  VT4C In Chinese or English; Interesting main site  [In Chinese. English here] 86SN7Audio PreamplifierPreamplifier
    842801A/845 push-pull Preamplifier  JP  Direct Heating Look at all those interstage transformers! To understand this approach; see the main pages ( for the Sakuma method".  [In Japanese. English here] 275691,801A,845(2)Audio PreamplifierPreamplifier
    843Battery Powered Preamp using the 6088  US  Sparkbench Subminiature tubes 216088 (2)Audio PreamplifierPreamplifier
    844Fluence: 5687 WOT PreAmplifierna  Nuance and Fluence Doesn't get much simpler 75687Audio PreamplifierPreamplifier
    8455687 WOT (With Output Transformer) PreAmplifierna  Nuance and Fluence From Turkey. 75687Audio PreamplifierPreamplifier
    846Simple Preamplifier  US  Carrion Sound Says This circuit can use most miniature 7-pin pentodes: 6AK5;6AU6;6CB6;6BA6; etc. 96AK5Audio PreamplifierPreamplifier
    847ECC88 Amplifier Circuitna  Audioton I'm not sure if this is a preamp or a final stage. Push Pull.  [In Polish. English here] 14ECC88Audio PreamplifierPush Pull
    84812AU7 Preampna  Bonavolta Note the high and low impedance outputs. Also notice the explicit schematic of the separate inputs and outputs. This would be a useful preamp to have around 1012AU7Audio PreamplifierPush Pull
    849Phono Amp; RIAA, with 6DJ8  US  Tube Builder Schematic only. 246DJ8Audio PreamplifierRIAA Amp
    850MC Head Amplifier  JP  Passionate Tube ASCII schematic is hard to read.  [In Japanese. English here] 2312AX7 (2)Audio PreamplifierRIAA Amp
    851The PhonoDude RIAA Amplifier  DE  DDDAC PCB Version 255755(2), ECC83(2)Audio PreamplifierRIAA Amp
    852Three Tube PHONO (RIAA) Preamplifiers with ECC83  na  Sam's Circuits Schematics only. (Three cricuits).  [In Greek. English here] 15ECC83Audio PreamplifierRIAA Amp
    853RIAA Amp  SE  Jax Place Discussion of different approaches; active and passive  [In Swedish. English here] 145751 (2)Audio PreamplifierRIAA Amp
    8546C45 RIAA Phono Preamp  US  Jeremy Epstein Lots of math 146C45Audio PreamplifierRIAA Preamp
    855Octal RIAA Preamp  US  Jeremy Epstein Discussion of a different source of hum; and how to fight it. 246SL7, 6SN7Audio PreamplifierRIAA Preamp
    856LCR RIAA  NL  VT52 I'm new to RIAA; so I don't claim to know what I am talking about" 17437A, EC8010Audio PreamplifierRIAA Preamp
    857RIAA and LINE - Preamp  DE  Roehrenkramladen Sleek.  [In German. English here] 16ECC83Audio PreamplifierRIAA/Line Amplifier
    8586DJ8 Mini Preamp  JP  Lagarto He shows an RIAA version in schematic; also.  [In Japanese. English here] 136DJ8Audio PreamplifierSRPP
    859ECL 82 Driver  IT  Galavotti's ECL82 is a triode/pentode tube.  [In Italian. English here] 28ECL82Audio PreamplifierSingle Ended
    860DHT preamplifier using the 1H4  NL  VT52 He shows Before and After pictures that result from a search and destroy mission for microphonics 81H4Audio PreamplifierSingle Ended
    861Full Service Preamp  US  Fi Primer Schematic is at 326DJ8 (2)Audio PreamplifierSingle Ended
    862Line Preamplifier  US  D Normolle There is a line stage and also a headphone amplifier project 1212B4, 6BX7 (2)Audio PreamplifierSingle Ended
    863Preamp Number 1na  Audioton Looks like they are using the two halfs of the tube in parallel?  [In Polish. English here] 16ECC88Audio PreamplifierSingle Ended
    864Preamp Number 2na  Audioton Looks like a 2-stage use of the tube  [In Polish. English here] 12ECC88Audio PreamplifierSingle Ended
    865Wzm. Sluchawkowy?na  Audioton Looks like a preamp. Help with translation?  [In Polish. English here] 13ECC83Audio PreamplifierSingle Ended
    866Pencil tube Preamp project  DE  AlexTubes Translated from the German  [In German. English here] 256021(2),6111Audio PreamplifierSubminiature tubes
    867Volume control preamp-o.p.t.  NL  VT52 An experiment. He combined the volume control and the out transformer. And look at the picture! 100% clip lead construction! 326Audio PreamplifierVolume-OPT
    868The Blue Velvet Line Preamplifier A DIY Project  US  Black Dahlia The power supply is more complex than the amp. 146SN7Audio PreamplifierX
    869QRP Transmitter 1933  US  Flickr You can probably figure out the schematic from the picture. Notice the connections are strips of; I guess; brass. Note the bulb with wire. I'm guessing at the tube. 930CW Ham Transmitter1 - 5 Watts
    870Transmisor QRP con válvula 6K8  ES  EA QRP Club From a Spanish QRP on-line journal  [In Spanish. English here] 226K8CW Ham Transmitter1 - 5 Watts
    871CW zender voor 40m  NL  HB Thui(s)brouw In Dutch  [In Dutch. English here] 146146BCW Ham Transmitter1 - 5 Watts
    872Roehrensender fur ein Wetterballon  DE  Jogis Roehrenbude “Tube transponder for a weather balloon”.  [In German. English here] 14DF96, DC97CW Ham Transmitter1 - 5 Watts
    873One Tube Push Pull Transmitter  US  Glowbugs From the Radio Handbook (which is quite worth buying) 1053CW Ham Transmitter1 - 5 Watts
    874Jones All-Band Exciter (1935 Model)  US  Glowbugs From the Radio Handbook (which is quite worth buying) 2353, 2A3CW Ham Transmitter1 - 5 Watts
    87553-2A3-210 Multi-Band Transmitter  US  Glowbugs From the Radio Handbook (which is quite worth buying) 3653, 2A3, 210CW Ham Transmitter1 - 5 Watts
    87612V Tube Transmitter Kit  US  Past Time Projects No schematic; try other projects; this is a nice-looking quick build 1212A5, 25L6(4)CW Ham Transmitter1 - 5 Watts
    8776V6 Transmitter Kit  US  Past Time Projects Third project on page. No schematic, but see other 6V6 transmitters; they're simple. 116V6CW Ham Transmitter1 - 5 Watts
    878Tube rigs from AE4GX  US  AE4GX No schematics; but you can figure them out 12[-]CW Ham Transmitter1 - 5 Watts
    8795763 40m CW transmitter  US  K5DH From the 1971 ARRL Radio Amateurs Handbook 125763CW Ham Transmitter1 - 5 Watts
    880The Novice Special: An Old Classic Revisited  US  WD4NKA From WD4NKA 226C4, 5763CW Ham Transmitter1 - 5 Watts
    88112AU7 Transmitter  US  T Williams Schematic Only 1412AU7CW Ham Transmitter1 - 5 Watts
    882Basic Triode Transmitter  BR  Teoria In Portugese; from Brazilian manual apparently. (See page 1)  [In Portugese. English here] 12203ACW Ham Transmitter1 - 5 Watts
    883Basic Tetrode or Pentode Transmitter  BR  Teoria In Portugese; from Brazilian manual apparently. (See page 2)  [In Portugese. English here] 12807CW Ham Transmitter1 - 5 Watts
    8846BM8 Single Valve TX for 80M and 40M  AU  ARNSW Go to page 5 286BM8, ECL82CW Ham Transmitter1 - 5 Watts
    885THE LG QRP TRANSMITTER PROJECT  UK  G3YUH See towards the bottom of the page for the schematic 22EF80, 5763CW Ham Transmitter1 - 5 Watts
    886K1BSX version of Hartley 1929 Type Transmitter  US  W1UJR From the 1929 article in QST on Hartley oscillators. See for commentary 11UX-210CW Ham Transmitter1 - 5 Watts
    887Hartley 1929 Type Transmitter  US  W1UJR A 1929 article on overhauling the transmitter for 1929". Lots of technical analysis; etc. 11UX-210CW Ham Transmitter1 - 5 Watts
    888Der Langstwellensender Goliath  NL  German Comm This is the monster transmitter used by the Kreigmarine in WWII to communicate with its U-Boats. My junkbox is not up to this. Yet. (15/60 Khz, 300/900 KW)  [In German. English here] 85RS301(6)CW Ham Transmitter1 MW
    889Spark-gap transmitter  US  Wikipedia From Wikipedia 4[-]CW Ham Transmitter1 Watt
    890The 40M Butt-Buster QRP Transmitter  US  EC Indiana QRP No schematic. But very nice history of how it the rig came to be with the help of many others. 156L6CW Ham Transmitter1 Watt
    891Attempt 78: CW Transmitterna  Radiomann Third project halfway down page. Author modifies a Radiomann to be an CW Transmitter. ECC82 is a 12AU7  [In German. English here] 8ECC82CW Ham Transmitter1 Watt
    892One-Tube QRP Transmitter for 40 or 80 Meters  US  OSE Electronics Really different: combines IC; Transistor and Tube. Includes 12V to 150V voltage multiplier 263A4CW Ham Transmitter1 Watt
    893QRP Transmitter  US  KL7H Looks like a one-evening project to me. Watch the hot power supply though. 116AR5 (2)CW Ham Transmitter1 Watt
    89410 Meter AM QRP  US  WD8DAS Looks pretty simply for AM 306AU8, 6C4, 6AQ5CW Ham Transmitter1 Watt
    895Simple Electron Tube Transmitter  US  T Pub Electron tube? 8TriodeCW Ham Transmitter1 Watt
    896Test transmitter  FR  Riethmuller In the middle of the page  [In French. English here] 10201A (?)CW Ham Transmitter1 Watt
    897QRP Transmitter for the 48 Meter Band  NL  Radio Morningstar Schematic Only.  [In Dutch. English here] 22ECL82, EL91CW Ham Transmitter1 Watt
    898Small Transmitter  NL  Radio Morningstar Schematic Only.  [In Dutch. English here] 12EL84CW Ham Transmitter1 Watt
    899One Tube Transmitter for the Novice  US  N8IE From 1971 issue of QST 236T9CW Ham Transmitter1 Watt
    9006AG7 Transmitter  US  KA1UNW Some of feedback capacitance is supplied by tube itself;" Check out photo at 106AG7CW Ham Transmitter1 Watt
    901Gootwairn VFO  US  KA1UNW Main page: for photos; text 136AC7CW Ham Transmitter1 Watt
    902French VFO  FR  Lamps Radio This looks like a different approach  [In French. English here] 302216 (3), E406NCW Ham Transmitter1 Watt
    903Basic Spark Transmitter  US  Antique Radio Title refers to the Queen of Induction Coils". (Is there a king?) 6[-]CW Ham Transmitter1 Watt
    904AM Transmitter  US  Big Nick's See the last project on the page. The tube is a guess of mine. 141S5CW Ham Transmitter1 Watt
    905Jones 1936 Push-Pull Transmitter  US  WV7G This looks like a perfect approach for first-time builders. 96J6CW Ham Transmitter1- 5 Watts
    90640 Meter QRP Transmitter  US  WA2NTK From WA2NTK. Simple design. 116AQ5CW Ham Transmitter1-5 Watts
    907A ONE TUBE 50C5 2 WATT TRANSMITTER  CA  Homebrew Radio Use an isolation transformer; please! This circuit is a dangerous way to save money on parts. 1650C5CW Ham Transmitter1-5 Watts
    908Tube Transmitter with 5763 PA  US  KD1JV Uses grid block keying" 346AW8A,5763CW Ham Transmitter1-5 Watts
    909Bills Glowbug Project #1  US  AB4YD Somewhat rough. Change the .jpg" designator. 266AG7,12GT5CW Ham Transmitter1-5 watts
    910Bills Glowbug Project #2; 6AB6, 12GT5  US  AB4YD Didn't work too good. OK anyways.. Change " Change "gbtx01.htm"; to "gbtx01.jpg" to "txosc1.jpg"; and "gb12gbt.jpg" 186AG7,12GT5CW Ham Transmitter1-5 watts
    91125 Watt Transmitter  BR  Teoria Chapter from the Radio Handbook of; apparently; the 1930's; Exciters and Low Powered Transmitters" 376SJ7, 6SK7, 807CW Ham Transmitter10 - 50 Watts
    912Klystron Oscillator  UK  G4OEP Scroll down to see a simple schematic for an oscillator 5KlystronCW Ham Transmitter10 GHz
    913Frank Jones 10 watt push pull crystal "beginners transmitter"  US  Glowbugs Classic simple design. Link to schematic. 136A6CW Ham Transmitter10 Watts
    914VA3AWA TPTG P-P Transmitter  CA  Old Radio Builder Rail-type construction. Nice. 1210(2)CW Ham Transmitter10 Watts
    915Homebrew 1934 Transmitter  US  WA1KPD Uses 46/10/203. Nice looking construction. 2146,10,203CW Ham Transmitter10 Watts
    916Spark Gap Transmitter  UK  Flight Refueling ARS Of course; using this would be ILLEGAL. 5[-]CW Ham Transmitter10 Watts
    917A Powerful CW Transmitter for Newcomers  US  Glowbugs Jones Push-Pull 6L6 circuit from 1937 book for new amateurs 126L6(2)CW Ham Transmitter10 Watts
    918Transmitter by 8BN; 1920's  FR  Lamps Radio Not sure if I understand this page.  [In French. English here] 1410CW Ham Transmitter10 Watts
    919100 Watt Transmitter  US  Phatty's Corner Schematic only. 316AG7, 807 (2)CW Ham Transmitter100 Watts
    920150 Watt CW 20-Meter Transmitter  US  Glowbugs From the Radio Handbook (which is quite worth buying) 336A6, 801, 50TCW Ham Transmitter100+ Watts
    921AA7JC 40 Meter CW Oscillator  US  Ken Lotts Schematic only. Uses 6DQ6 tube, which is fun. 12 watts straight out - crush those crystals. Beautiful picture at 156DQ6CW Ham Transmitter12 Watts
    92213-13.2MHz Mixer VFO  UK  G4OEP Pencil tube circuit with pictures of really retro construction. Nice! 17XFY43CW Ham Transmitter13 MHz
    923My New 6L6 Transmitter  US Nice story of a new builder and his approach. 136L6CW Ham Transmitter15 Watts
    92440 Meter CW  US  Ken Lott's Excellent photos, layout, and labelling. Schematic is AA7JC. 196Q6,0D3CW Ham Transmitter15 Watts
    9256J5/6L6 Transmitter  US  W0VLZ Loads up to 15W. 216J5, 6L6CW Ham Transmitter15 Watts
    926Transmissor 2W com válvula 6AQ5  ES  PY2MG Scroll down about 1/3 the way through the page  [In Spanish. English here] 296AQ5CW Ham Transmitter2 Watts
    927Homebrew 1929 Transmitter  US  WA1KPD Uses a 10 or 45 tube. 160, 80, or 40. Schematic is from 1929 Handbook 1210CW Ham Transmitter2 Watts
    928Low power, Crystal Controlled Transmitter  US  Antique Radios From QST, 1927 (scroll down for article) 12201(2)CW Ham Transmitter2 Watts
    929Dirt Simple 40 Meter Transmitter  CA  Homebrew Radio From 1968 Popular Electronics 56AQ5CW Ham Transmitter2 Watts
    930Tube Transmitter with 5763 PA  US  KD1JV Quite a mixture of tubes, transistors, Ics, etc. 506AW8, 5763CW Ham Transmitter2 Watts
    931Transmissor com 6DQ6 - PY1DAS  BR  813AM Schematic only  [In Portugese. English here] 286V6, 6DQ6CW Ham Transmitter2 Watts
    932Swell 40/80 Meter CW Transmitter  US  Edsel Motors "Cool 2 Tube Retro" Design. 25 Watts. No schematic, but you can guess at it. 1512AT7, 6L6CW Ham Transmitter25 Watts
    93330W medium-wave transmitter  DE  Geisslerroehre Used in their Tesla experiments  [In German. English here] 30PL504CW Ham Transmitter30 Watts
    9341958 Novice Transmitter  US  K3HLN For 80; 40 and 15. (Homework assignment: add 20 meters). Over half the parts are the power supply. 345U4, 0D3, 6BQ5CW Ham Transmitter30 Watts
    935Easy Driver Xtal Transmitter  US  KA1UNW See links to photos; circuit explanation at 406AG7, 6DQ6CW Ham Transmitter30 Watts
    9364 Watts on 24 GHz  NL  PA0EHG Consider this a specialty" experiment. If you can find the tube and have the receiver; should be fun. He tested the output by holding his finger in front of the waveguide. 4848 HDCW Ham Transmitter4 Watts
    937FPA8 4-Watt Transmitter  US  ARRL Use in a 1950s DX-pedition 393A5, 3D6, 3A5CW Ham Transmitter4 Watts
    938Two-Tube 40M CW Transmitter  JP  JA9TTT Schematic Only. Japanese. What is a CZ-501 tube?  [In Japanese. English here] 24CZ-501D, CZ-504CW Ham Transmitter40 Meters
    939SM7UCZ 80 Meter Transmitter  UK  G3PTO Schematic is half-way down page. 146L6CW Ham Transmitter5 - 10 Watts
    9406AQ5 CW Transmitter  US  K5DH Hmmm; six parts. I wonder what it sounds like. I like the neon bulb tuning system. 66AQ5ACW Ham Transmitter5 - 10 Watts
    94180 Meter Tube Transmitter  SE  Tube Radio From Jan SM5GNN  [In Swedish. English here] 17ECL82CW Ham Transmitter5 - 10 Watts
    942XFY 43 VFO  UK  G4OEP Pencil tube circuit with pictures of really retro construction. Nice! 17XFY43CW Ham Transmitter5 MHz
    94350C5 Bare Essentials Transmitter  CR  Dragan Nikolic Change "transmitter" in the URL to see the explanation. 950C5CW Ham Transmitter5 Watts
    944Three Tube Transmitter  UK  G0UPL From Frank Harris; Chapter 14. Very detailed and extensive. A good starting point. 3641(2),6L6CW Ham Transmitter5 Watts
    9455W VHF Oscillator  DE  Geisslerroehre For physics experiments; not specifically communication.  [In German. English here] 25EL84 (2)CW Ham Transmitter5 Watts
    9466L6 CS Transmitter  US  WS1K Now that's they way I build! 100% junkbox on a breadboard. 86L6CW Ham Transmitter5 Watts
    947One-Valve CW Transmitter  AU  P. Parker From 1973 ARRL Handbook 226GV8CW Ham Transmitter5 Watts
    9485-Watt Single Valve Tube  DE  DL9EBA German project 166BQ5CW Ham Transmitter5 Watts
    949Sender mit Röhre RS291  DE  DL9EBA What a great tube! Look at the picture!  [In German. English here] 14RS291CW Ham Transmitter5 Watts
    9506L6 Homebrew Transmitter  US  WA1KPD Links to schematic, etc. 176L6CW Ham Transmitter5 Watts
    951AMECO CW Transmitter AC-1  NO  LA5KI Nice pictures and schematic 136V6CW Ham Transmitter5 Watts
    952Crystal Transmitter  NL  Radio Morningstar Schematic Only.  [In Dutch. English here] 30EL91, ECC83, 807 (2)CW Ham Transmitter5 Watts
    953Transmitter made from lamps  FR  Lamps Radio Two different approaches on this page  [In French. English here] 1210YCW Ham Transmitter5 Watts
    95490 Watt CW Rig  US  Glowbugs From the Radio Handbook (which is quite worth buying) 3653, 2A3, 210 (2)CW Ham Transmitter50 - 100 Watts
    955DX-20 Clone  US  K5DKZ Extensive construction discussion and pictures. 4312BY7A,6DQ6BCW Ham Transmitter50 Watts
    956Homebrew 6146B Transmitter  US  WB6KWT The schematic has be clicked on in different places. 346DS5,12AX7,0C3,0B3,6AG7,6146BCW Ham Transmitter50 Watts
    95780m to 20m 815 ECO Transmitter  US  Dipsey Dumpster “Electron Coupled Oscillator”. Magazine article from the 1950's 526K7, 6K7, 6Q7, 6E5, 89, 6V6, 815CW Ham Transmitter50 Watts
    958Inexpensive 75-watter  US  Glowbugs 5 band HF. Takes 1000 volts on plate 3012BY7,1625CW Ham Transmitter75 Watts
    959A Single-Tube 75-Watt Novice Transmitter  US  N6EV From 1957 ARRL Handbook (page 173) 246146CW Ham Transmitter75 Watts
    960A 75-Watt 6DQ5 Transmitter (6AG7 / 6DQ5)  US  N6EV From 1961 ARRL Handbook (page 179) 356AG7, 6DQ5CW Ham Transmitter75 Watts
    961Oven Magnetron as a 13cm TX ?  SL  S57UUU They got 800W out at 2460 MHz. Basically; a magnetorn is a 4 Kv Zener Diode; so you need a constant current source". 30MagnetronCW Ham Transmitter800 Watts
    962A 7-Band 90-Watt Transmitter  US  N6EV From 1957 ARRL Handbook (page 179) 456AK6, 6C4(3), 6146CW Ham Transmitter90-Watts
    9631 mW Transmitter  UK  G4JCP I'm not sure if that's the real power figure. Looks more like 100 MW would be possible with 12V on the plate. Thoughts? 16DL96CW Ham Transmitter< 1 Watt
    964Tiny Spark Gap Transmitterna  Radiomann 1/3 way down page; section beginning Funksender". Simple sparker. Maybe you could get away with this as an experiment.  [In German. English here] 2[-]CW Ham Transmitter< 1 Watt
    965CW Transmitter w/Homemade Semiconductor  US  Spark, Bang, Buzz Not a tube rig; but even more primitive; so it's included here. See bottom of page. 7[-]CW Ham Transmitter< 1 Watt
    9661 TUBE ALL BAND TRANSMITTER ( QRP )  CA  Homebrew Radio Five parts? I wonder what this sounds like. 500 mW. 56AQ5CW Ham Transmitter< 1 Watt
    967QRP Transmitters with Ceramic Resonators  NO  LA8AK I threw this in because I was wondering what it would take to do a tube rig based on one of these.  [In Norwegian. English here] 11[-]CW Ham Transmitter< 1 Watt
    96810 GHz FM ATV Transmitter  UK  RAF ARS OK; it is not a tube rig; but my idea is to do a tube-based version (except for the Gunn diode) 50[-]CW Ham Transmitter< 1 watt
    969Twin Tube 80  US  No GA QRP From Mike Branca and the NoGA QRP Club 12[-]CW Ham Transmitter< 2 Watts
    970Electromechanical RF Transmitter  US  MJ Rainey Run a stepper motor at 3000 RM, get 10 Khz sine wave, run through three 7x electromagnetic frequency multipliers 21[-]CW Ham TransmitterElectromechanical
    971Junkbox QRP transmitter  CA  Vintage Ham One tube. Simple non-commerical components 346AG7, 807 (2)CW Ham TransmitterHF - 100+ Watts
    972Frank Jones 6J6 QRP transmitter  US  AK0B Cute! One tube; and very small. 15[-]CW Ham TransmitterHF, 1-5 Watts
    973Two Tube transmitter  US  WA5VLZ From 1940 Stnacor Hamanual 156J5, 6L6CW Ham TransmitterHF, 10+ Watts
    974A TNT Transmitter  US  WA5VLZ Tuned-plate-not-tuned-grid" transmitter; from 1930 ARRL Handbook. Pair of 45's in push-pull. 845 (2)CW Ham TransmitterHF, 10+ Watts
    975The Mighty Midget - A 10-Watter for 80 and 40  US  N6EV From 1966 QST 256GW8CW Ham TransmitterHF, 10+ Watts
    976AI2Q's 6L6 Transmitter  US  N6EV 9th on the Schematics and Projects List 266L6CW Ham TransmitterHF, 10+ Watts
    97740 Meter MOPA Transmitter  US  WB4WHH With VFO or Crystal 256AG6, 6L6GCCW Ham TransmitterHF, 10+ Watts
    978Bare-essentials transmitter  US  WD4NKA Uses a 50C5 so no transformer. This is dangerous - at least put in an isolation transformer. 1350C5CW Ham TransmitterHF, 10+ Watts
    9796AG7-6L6 MOPA transmitter  US  WD4NKA MOPA = Master Oscillator Power Amplifier 206AG7-6L6CW Ham TransmitterHF, 10+ Watts
    9801 - Röhren - 5 Watt - Telegraphie - Sender  DE  DL9EBA Based on 1-tube German WWII spy radio. Cool looking.  [In German. English here] 8EBL21CW Ham TransmitterHF, 5-10 Watts
    98140/80m CW Transmitter  UK  Hans Summers More complex; but nice-looking 50ECL82CW Ham TransmitterHF, 5-10 Watts
    982One-tune 6L6 Classic Transmitter  US  WA5VLZ From 1939 Stancor 25-B design 156L6CW Ham TransmitterHF, 5-10 Watts
    983Hartley Single Tube Transmitter  US  Glowbugs Uses one 6SN7. Simple it is. Author says ANY triode should be workable. 96SN7CW Ham TransmitterHF, 5-10 Watts
    984Cigar Box 6 Watt Transmitter  US  W1FIF Uses 6c5 for oscillator; 6V6 for amp 186C5, 6V6CW Ham TransmitterHF, 5-10 Watts
    985AMECO AC-1 two-tube Cwtransmitter  US  WB1GFH Nice looking; basic rig. 206X5, 6V6CW Ham TransmitterHF, 5-10 Watts
    986Classic CW Transmitter  US  WB4WHH Top of Page. With info for 80/40/30 bands. 176AG6CW Ham TransmitterHF, 5-10 Watts
    987Simple One-Tube Tri-Tet Transmitter  US  WB4WHH From Byron Goodman's 1936 QST article 96L6CW Ham TransmitterHF, 5-10 Watts
    988One-valve 80m transmitter  UK  G4KKI He has an extension which adds another tube 20ECL82CW Ham TransmitterHF, 5-10 Watts
    98980/40 meter CW transmitter with 6BM8/ECL82  SE  Jax Place European-oriented parts. Interesting commentary; including an implication that you can easily add a mic for AM 25ECL82 (6BM8)CW Ham TransmitterHF, 5-10 Watts
    990Phoenix 20-meter Transmitter (G3YUH)  UK  G3YUH Has plans to modify it to handle 40 meters as well. 19EF80, 5763CW Ham TransmitterHF, 5-10 Watts
    991Simple Breadboard 40M Transmitter  US  N2ZHS No schematic; but you can probably tell what to do by looking at the wires. 9[-]CW Ham TransmitterHF: 1-5 Watts
    992An Early 1920's One Tube Transmitter  US  Antique Wireless Based on 1920 design; with later tube 136CK4CW Ham TransmitterHF: 1-5 Watts
    99320 Mhz; 10 Watt R.F. Generator  US  Glowbugs Apparently schematic only. 14829BCW Ham TransmitterHF: 10+ Watts
    994A 35 Watt; 2 Band Transmitter Philosopher  US  Glowbugs File is in different formats 2860C5,6AQ6,6AK5CW Ham TransmitterHF: 10+ Watts
    99565 Watts at Low Cost  US  Glowbugs File is PDF. 356K6,6BG6(2)CW Ham TransmitterHF: 10+ Watts
    996Series Modulated 807 (40W transmitter); No Modulation Transformer Needed  US  AM Window No commentary other than what's in the schematic 4512AU7,6LF6,6AG7,807CW Ham TransmitterHF: 10-50 Watts
    997Homebrew 813 AM Transmitter  US  WB4GWA 500 watts input 496SL7, 6H6, 6J5, 6SN7, 813 (2)CW Ham TransmitterHF: 100+ Watts
    998Power Hartley transmitter using a 1 kW GM100 triode  UK  Thermionic Schematic is in the middle of the page under the third project. 14GM100CW Ham TransmitterHF: 100+ Watts
    999One-valve QRP CW Transmitter by Raimo Jarvi OH8MNM; Finland  UK  Hans Summers Puts out 6W on 40 Meters 27PCL86 (2)CW Ham TransmitterHF: 5-10 Watts
    1000Construccion de Un Transmisor Push-Pull con Bulbos 245  ES  Radionet From a 1932 Mexican publication  [In Spanish. English here] 13245 (2)CW Ham TransmitterHF: 5-10 Watts
    10016DQ6B Transmitter  US  SubDevo No photo or discussion; schematic only 326DQ6BCW Ham TransmitterHF: 5-10 Watts
    10026L6 Rig  US  AM Window No schematic. Nice finish; though 96L6, MagicEyeCW Ham TransmitterHF: 5-10 Watts
    1003Single 10 Shunt Fed Hartley Oscillator for 80 meter CW  US  AB0CW From 1932 QST article 1810CW Ham TransmitterHartley
    10041929 MOPA ( Master Oscillator Power Amplifier ) 80 meter transmitter  US  AB0CW The oscillator and power amplifier are presented separately so they can be broken apart. 2627 (2), 865CW Ham TransmitterMOPA
    100580 m MOPA CW transmitter using three 2A5 pentodes  US  AB0CW Looks simple enough. 292A5 (3)CW Ham TransmitterMOPA
    100640 meter MOPA transmitter using a '10 triode TNT oscillator driving an 860 PA  US  AB0CW From March 1931 QST 2810, 860CW Ham TransmitterMOPA
    10072-Tube MOPA Transmitter  CA  Vintage Amateur Breadboard layout. 16210(2)CW Ham TransmitterMOPA
    1008Relaxation Oscillator with Home-made Triode  US  Spark, Bang, Buzz The title pretty much says it all. This is ultimate homebrew. Can it work on the air? 6[-]CW Ham TransmitterNon-Traditional
    1009Magnetic AM Broadcaster  US  Spark, Bang, Buzz Transmits by magnetic field. 6[-]CW Ham TransmitterNon-Traditional
    1010Broadcast a signal on a magnetic field  US  Spark, Bang, Buzz OK; I have to try this. He says one turn of wire around the house fed by a transistor radio will create a magnetic signal that fills the house. 1[-]CW Ham TransmitterNon-Traditional
    1011G4OO Tube Transmitter and Receiver  UK  Spalding / District No schematic; my parts counts as a guess. Nice pictures and photos, though 526SG7,6BA6(2),ECH81,ECL80,807(2)CW Ham TransmitterPush Pull
    1012EduKit Transmitter  US  Boatanchors Schematic in the photo towards bottom. Remember the isolation transformer 206C5, 6SD7(2)CW Ham TransmitterRegenerative
    1013Funkeninduktor  DE  Jogis Roehrenbude “Spark-Coil Transmitter”. Nice pictures.  [In German. English here] 3[-]CW Ham TransmitterSpark Coil
    1014Uralter Funkeninduktor  DE  Jogis Roehrenbude “Older Spark-Coil Transmitter”. Nice pictures.  [In German. English here] 3[-]CW Ham TransmitterSpark Coil
    1015Carbon Arc Transmitter  US  N9VV He implies that this could be used for voice. How? 8[-]CW Ham TransmitterSpark Gap
    1016Spark Transmitter.  US  N9VV Nice workmanship. No Schematic. 4[-]CW Ham TransmitterSpark Gap
    1017Replica Spark Gap Transmitter; circa 1919  US  AB0CW Seems to be in the 200 meter band. 10[-]CW Ham TransmitterSpark Gap
    1018Carbon Arc RF Oscillator  US  Spark, Bang, Buzz Pre-tube. Too bad it's illegal to put one of these on the air. Isn't there some way to filter out the noise; harmonics; etc.? 6[-]CW Ham TransmitterSpark Gap
    1019Simple Spark Transmitters.  US  Spark, Bang, Buzz Middle of Page. This page also has a Spark Coil Transmitter and a Barbecue Lighter Transmitter. 4[-]CW Ham TransmitterSpark Gap
    1020Spark Gap Transmitterna  Sudan Ham I've never worked the Sudan . . .  [In Arabic. English here] 4[-]CW Ham TransmitterSpark Gap
    1021Spark Gap Transmitters  US  K8CIX No schematics; although the radios are simple enough that you can supply your own. The detailing in the photos is excellent. 10[-]CW Ham TransmitterSpark Gap
    1022Spark Coil Transmitter and Branley Coherer  US  Boatanchors No schematic; but these are all based on the same idea. I like this construction approach. 6[-]CW Ham TransmitterSpark Gap
    1023Spark-Gap Transmitter  SE  Harry's Homebrew If you want to get rid of your license real fast . . . 8833 (2)CW Ham TransmitterSpark Gap
    1024Singing Arc Carbon Arc Transmitter  AU  Adventures Cybersound More depth on the subject. Several versions are discussed. 6[-]CW Ham TransmitterSpark Gap
    102512BY7A Transmitter  JP  JA9TTT Schematic Only. Japanese. Is there any commentary on this?  [In Japanese. English here] 286CB6, 12BY7ACW Ham TransmitterVXO
    1026Three Stage VXO Transmitter  JP  JA9TTT Schematic Only. Japanese. Is there any commentary on this?  [In Japanese. English here] 31CZ-501D(2), CZ-504CW Ham TransmitterVXO
    1027Jones Transmitter  DE  DK3BI Very simple arrangement  [In German. English here] 123A5CW Ham TransmitterX
    1028AA8V/W8EXI 6CL6 One-Tube Transmitter  US  Greg Latta VERY complete layout and construction commentary 166CL6, 0B2 (2)CW Ham TransmitterX
    1029The AA8V/W8EXI 6CL6 One-Tube Transmitter  US  Greg Latta Excellent circuit analysis and discussion 156CL6CW Ham TransmitterX
    1030Cigar Box Transmitter  US  Alfa Lima Int. From 1955 Practical Wireless 151S4 (2)CW Ham TransmitterX
    1031Single-Valve Transmitter  US  Hall Article from Practical Wireless"; 1957. Says can be used for AM with a simple modification. Maybe worth a try. 13ECL80CW Ham TransmitterX
    1032A TUBE 40 METER CW QRP TRANSMITTER  US  Glow Bug Kits Really cute. I'd like to try this. 96AQ5CW Ham TransmitterX
    1033Alltoobs CW Transmitter  US  N5FC In an Altoids can. Naturally. 1512BY7, 6AG7CW Ham TransmitterX
    1034Ham AM Transmitter  US  KM5TZ Fascinating. We get to watch the birth of new Texas Kilowatt! And I thought the stork brought them. 354-125 (4)CW Ham TransmitterX
    1035LA6NCA Two-Tube Transmitter  NO  LA6NCA From a 1955 design in the ARRL Handbook.  [In Norwegian. English here] 226AG7,6L6CW Ham TransmitterX
    1036One Tube 40 Meter CW Transmitter  US  Ken Lotts Nice finish 146DQ6CW Ham TransmitterX
    1037WB2MIC 6L6 Transmitter project  US  WB2MIC Original article September 1968 Electronics Illustrated James White W5LET 156L6CW Ham TransmitterX
    1038Push-pull; crystal-controlled, two-tube, 5 meter transmitter  US  Glowbugs Apparently schematic only. 16807 (2)CW Ham TransmitterX
    1039813 Crystal Oscillator  US  Glowbugs Apparently schematic only. 16813CW Ham TransmitterX
    1040Push-Pull Hartley Transmitter  US  Glowbugs Apparently schematic only. 1630 (2)CW Ham TransmitterX
    1041A Push-Pull Hartley VFO transmitter  US  Glowbugs Apparently schematic only. 16803CW Ham TransmitterX
    1042A Simple Grid Modulator  US  Glowbugs Not sure what book or magazine this is from. 206SL7, 6Y6GCW Ham TransmitterX
    1043Simple Transmitter  US  Glowbugs Simple; all right. File is PDF. 106V6CW Ham TransmitterX
    1044Tuned-Plate Tuned Grid Transmitter  US  Glowbugs Takes 1200 volts on the plate 22211 (2)CW Ham TransmitterX
    1045Push-Pull Crystal Oscillator by W5TVW  US  Glowbugs Apparently schematic only. 5050JY6CW Ham TransmitterX
    1046Bare-Essentials Transmitter with 50C5  US  Glowbugs Fourth project on page. From Electronics Illustrated; March 1968. I like the discussion on safety in this one. 1250C5CW Ham TransmitterX
    1047No Frills One-Tube Amateur CW Transmitter  US  Mother Earth From Mother Earth News" 126V6CW Ham TransmitterX
    1048TNT (tuned not tuned) transmitter 1930's style  US  N9VV From Frank Jones Circuit. 106SN7CW Ham TransmitterX
    1049PUSH-PULL 6SN7 transmitter  US  N9VV From Frank Jones Circuit. 86SN7CW Ham TransmitterX
    1050K9KEU's version of the 6SN7 push pull rig  US  N9VV See the K8LKC rig. 86SN7CW Ham TransmitterX
    1051One Tube Amplifier  US  OSE Electronics 80 and 40 meters for beginners 246T9CW Ham TransmitterX
    10526L6 crystal-controlled transmitter for 80 - 30 m CW  US  AB0CW From N6EV schematic. 156L6CW Ham TransmitterX
    105380M VFO rig with 807 final  US  AB4YD I love this get to it" approach. 486C4, 6AC7, 6V6 (2)CW Ham TransmitterX
    10546L6 Transmitter  US  K4GC Another cakepan rig. Explain to me again how the 0D2 works? 166L6, 0D2CW Ham TransmitterX
    1055Novice Transmittter  US  K5DH Another test: can you build the circuit from the close-up photos without a schematic 166AG7, 6L6CW Ham TransmitterX
    1056K5DH's 807 CW Transmitter  US  K5DH From K5DH. 366AG7,807CW Ham TransmitterX
    105740m 6L6 CW Transmitter  US  K5DH From K5DH. 206C5,6L6CW Ham TransmitterX
    10586T9 Transmitter  US  KD6CC Uses a Compactron tube. No schematic; but should be readily available from ARRL Handbook. 156T9CW Ham TransmitterX
    1059N0GA Twin Tube 80  US  KL7H A quick juck box special with some different ideas. For 80 and 40 106AR5 (2)CW Ham TransmitterX
    1060A One-Tube Two-Band Transmitter for the Novice  US  N6EV From 1957 ARRL Handbook (page 170) 176AG7CW Ham TransmitterX
    106175 Watts on Four Bands  US  N6EV From 1957 ARRL Handbook (page 176) 366AG7, 6L6GB(2)CW Ham TransmitterX
    1062Three Band Oscillator Transmitter for Novice (6DQ6A)  US  N6EV From 1961 ARRL Handbook (page 172) 306DQ6ACW Ham TransmitterX
    1063All-Band Inexpensive 40-Watt Transmitter (6AG7 / 1625)  US  N6EV From 1961 ARRL Handbook (page 175) 306AG7, 1625CW Ham TransmitterX
    1064A 90-Watt All-Purpose Amplifier (6146)  US  N6EV From 1961 ARRL Handbook (page 183) 406146CW Ham TransmitterX
    10656AQ5A QRP 80M/40M Transmitter  US  N6EV By Scott Brigham; AA0HU 196AQ5ACW Ham TransmitterX
    10666BM8 Xmtr by Lee Richey; WA3FIY  US  N6EV From N6EV's Glowbugs site. 356BM8CW Ham TransmitterX
    106710-Watt Transmitter  US  N6EV In Dutch 256BM8CW Ham TransmitterX
    10686L6 Scrounger  US  N6EV By Steve Smith; WB6TNL 136L6CW Ham TransmitterX
    1069Vackar VFO  US  N6EV Simpler than the parts count would suggest 28ECL80CW Ham TransmitterX
    1070G4VAM Valve Job  US  N6EV Simpler than the parts count would suggest 28ECL80CW Ham TransmitterX
    1071One-tube transmitter (80 meters)na  VE3BDB From Operation Home Brew" 19Uses a single 807 (!)CW Ham TransmitterX
    1072Micamold XTR-1 Transmitter  US  WA9WFA A three tube 25 watt transmitter that covers the amateur frequencies of 20 meters; 40 meters; and 80 meters." 196AG7,6L6CW Ham TransmitterX
    1073The Raider Transmitter  US  WD8DAS Fourth project down on the page. 375763 (2), 6146CW Ham TransmitterX
    1074One-Tube Transmitter for 80 and 40 (using 6AQ5)  US  SubDevo 6AQ5 Glowbug 156AQ5CW Ham TransmitterX
    1075One-sixty meter (1.8 MHz) Hartley transmitters  UK  Thermionic Looks simple enough. And like it might work. 11812ACW Ham TransmitterX
    1076Single valve eighty meter (3.5 MHz) transmitter  UK  Thermionic From RSGB magazine. So where do we get a schematic? 12807CW Ham TransmitterX
    1077MOPA Transmitter  CA  Vintage Ham Also nice construction. 21210 (2)CW Ham TransmitterX
    1078MOPA Transmitter  CA  Vintage Ham Second project on page. Looks like mid-1920s 1810 (2)CW Ham TransmitterX
    1079Toob Transmitter  US  W0CH That schematic isn't really helpful. 66CK6CW Ham TransmitterX
    108080 Meter Transmitter  US  WA8YWO Extremely simple design. 45V on the plate. Note the film canister tank coil. Total cost should be under $20. I wonder what it sounds like? 83A5CW Ham TransmitterX
    1081Ameco AC-1 NOVICE RIG  US  WA8YWO A replica of a 1950s cw transmitter kit. Are any tube kits like this still sold? 146V6CW Ham TransmitterX
    10826L6 Transmitter  US  VE1DY Classic Breadboard" 1676 (2)CW Ham TransmitterX
    1083MODEL 701 ATOM-X TRANSMITTER  US  BAMA Manuals Link to schematic is half-way down 296AQ5(3), 807CW Ham TransmitterX
    1084Homebrew 40-Meter Transmitter  US  N2ZHS No schematic; but you can figure it out from the board. 12[-]CW Ham TransmitterX
    1085An EL84 single tube CW/AM Transmitter  US  Glow Bug Kits I like whatever schematic program he used. 20EL84CW Ham TransmitterX
    1086Low Frequency Oscillator  US  Bliley Electric I guess any tube will do. Will it? 136J6CW Ham TransmitterX
    10872-Tube Transmitter for 80 meters  US  NS1W No schematic; but I believe you can figure it all out from the close-up photos of the parts 156146CW Ham TransmitterX
    1088AF4K's 6CL6-2E26 Transmitter  US  AF4K Doesn't seem too demanding; despite the parts count 316CL6,2E26CW Ham TransmitterX
    10892-Valve CW Transmitter  SE  Harry's Homebrew Kind of cute little rig. 206AK5, EL95CW Ham TransmitterX
    1090Single Valve Transmitter by Harry Lythall - SM0VPO  SE  Harry's Homebrew About as simple as you can get 7DF91CW Ham TransmitterX
    1091Cigar Box Transmitter  SE  Harry's Homebrew From March 1955 Practical Wireless" 181S4 (2)CW Ham TransmitterX
    1092Medium wave transmitter  DE  Alfa Lima Int. In German; but you can figure it all out.  [In German. English here] 76V6CW Ham TransmitterX
    1093Medium wave transmitter  DE  Alfa Lima Int. In German; but you can figure it all out.  [In German. English here] 9EL84CW Ham TransmitterX
    1094Morningstar medium wave transmitter  DE  Alfa Lima Int. Schematic only  [In German. English here] 23EF80,EL34CW Ham TransmitterX
    10952 Valve 40-Meter CW Transmitter  AU  P. Parker Schematic a little hard to read. 256AU6,6GV8CW Ham TransmitterX
    1096One Valve CW transmitter  AU  P. Parker Very much built from scrounged parts 216GV8CW Ham TransmitterX
    1097The EL Transmitter  US  AM Window EL84's are 6BQ5's 26EL84(2),EL90CW Ham TransmitterX
    1098A Screen Modulated Transmitter by NE1S  US  AM Window Schematic only. 4812AX7,6SN7,6080,6AG7,6DQ6CW Ham TransmitterX
    10991929 Hartley Transmitter Final  US  Antique Wireless I think this is the final for the 1929 Hartley. 2045(2)CW Ham TransmitterX
    11001934 Transmitter  US  Antique Wireless For 20 and 40 meters. 2247, 203ACW Ham TransmitterX
    11011929 Hartley Transmitter  US  Antique Wireless With comments on what to do about a rotten signal" 9203ACW Ham TransmitterX
    1102Slat Board Transmitter from K8ZT  US  ARRL Should be simple enough to find a schematic for this. Quick construction method. 1027CW Ham TransmitterX
    1103Tube Greetings From Moscow  DE  B Kainka An oscillator with low volts on the plate (12V; here)  [In German. English here] 51SH24CW Ham TransmitterX
    1104Bruce Howes 1934 Transmitter  US  W1UJR Quite cool looking 1746, 47 (2)CW Ham TransmitterX
    1105Three Tube Transmitter  US  W1UJR One of QST's Most Popular Designs" 25203A, 10, 47CW Ham TransmitterX
    11061929 Transmitter  US  W1UJR The article is from 1928. A whole lot of analysis here for a very simple rig. 11UX-210CW Ham TransmitterX
    1107The TNT Star: DIY speakers cable  IT  TNT Audio I should try some of these. 1[-]Construction HintsAudio Cable
    1108RC vs. LC Loading  NL  VT52 Best explanation I've seen 1[-]Construction HintsAudio Output Loading
    1109Ballast Tubes and Resistance Line Cords  UK  Vintage Components Anything to avoid paying for a transformer 0[-]Construction HintsBallast Tubes
    1110Identifying Ballast Tubes and Plug-in Voltage Dropping Resistor Units  US  Radio Remembered Great information that's hard to find. Never used one of these; though. 1[-]Construction HintsBallast Tubes
    1111Balun for Portable QRP Work  US  N0SS PDF File. I like the use of heat shrink tubing for non-wire use. 1[-]Construction HintsBalun
    1112Baluns, What they Are  US  W7EL And How they Do It. “The definitive balun article”. 1[-]Construction HintsBaluns
    1113Battery Tutorial  SE  Harry's Homebrew Focuses on NiCds 0[-]Construction HintsBatteries
    1114Biasing  US  Gabe's Tube Amps Basic theory and how-to 1[-]Construction HintsBiasing
    1115Experimentiergehause  DE  Erinacom “Experiment Housing”. Basically a breadboard system for tube experiments. Nice looking.  [In German. English here] 1[-]Construction HintsBreadboard
    1116Modern Tube Breadboard  DE  Elexs I've got to try one of these.  [In German. English here] 5[-]Construction HintsBreadboards
    1117Breadboard for vacum tube projects  DE  Radio Freak Basic and quick approach.  [In German. English here] 6[-]Construction HintsBreadboards
    1118Breadboard for tube radio testing  US  Dave Schmarder I have to make one of these. I have a messy one I did myself long ago, but this is beautiful. 20[-]Construction HintsBreadboards
    1119Opamp Design and Test Board (IC-based)  AU  Elliot Sound [Click to Project 41 from projects page.] Included here because I like the explanation of the hacksaw tool for PCB development. 15[-]Construction HintsBreadboards
    1120Triode breadboards  FR  Lamps Radio These are cool-looking triodes. Can they be bought anywhere?  [In French. English here] 10R36Construction HintsBreadboards
    1121Formteile - zum Beispiel Potie-Knöpfe - selbstgegossen   DE  Jogis Roehrenbude “Mouldings – for example Potie buttons – selfmade”. How to make buttons, etc. out of various hobby plastics.  [In German. English here] 1[-]Construction HintsButtons
    1122Using CAT 5 Cable for High-End Audio  IT  TNT Audio Some people are really in to this. 0[-]Construction HintsCables
    1123Homebrew Modification: Wooden Housing for Electrolytic for Audiophiles  NL  DHT Rob This article made my day. Dozens of pictures showing the steps to take the metal can off an electrolytic and encase it in beeswax; ricepaper (it really affects the sound!"); and a wooden housing.  [In Dutch. English here] 1[-]Construction HintsCapacitor
    1124Build Your Own Air Variable Capacitor  US High end production values 1[-]Construction HintsCapacitor
    1125Homebrew Capacitor  UK  Hans Summers Made with aluminum foil and Saran Wrap. 1[-]Construction HintsCapacitor
    1126Drehkondensator - selbstgebaut  DE  Jogis Roehrenbude In German. Homebrew variable condensor.  [In German. English here] 1[-]Construction HintsCapacitor
    1127Make Your Own High Voltage Capacitors  DE  Jochens High Voltage As in 35KV range. I like the capacitor made from a yogurt cup (Relatively thick PP as dialectric"). 1[-]Construction HintsCapacitor
    1128Baking Soda Variable Electrolytic Capacitor  US  Spark, Bang, Buzz A relative of the Borax Rectifier 1[-]Construction HintsCapacitor
    1129Make Your Own High Voltage Capacitors  CA  VA3AVR Careful; these can ZAP! 1[-]Construction HintsCapacitor
    1130Molded Mica Capacitor Codes  US  Radio Remembered I just measure them and write the value on a little sticker; but this is good information 1[-]Construction HintsCapacitor
    1131Make Cheap Steel Enclosures  US  Geofex I like the part about not really needing any tools except a hacksaw and a mallet. 1[-]Construction HintsChassis / Enclosures
    1132Using Circuit-Board Material to Build Cabinets  DE  DL2LUX In German; translated through Google  [In German. English here] 1[-]Construction HintsChassis / Enclosures
    1133Chassis Wiring Hints  NL  DHT Rob How to make good earth grounds; what types of wire to use (cotton sounds better"); etc. For audiophiles'  [In Dutch. English here] 1[-]Construction HintsChassis Wiring
    1134Homebrew Inductors  US  DX Zone PDF File. How to build quality transmitter coils 1[-]Construction HintsCoil Winding
    1135Coil winder using Dremel  ES  EA QRP Club From a Spanish QRP on-line journal  [In Spanish. English here] 5[-]Construction HintsCoil Winding
    1136Rook Coils for Crystal Sets  US  Rook Coils Basket weaving 0[-]Construction HintsCoil Winding
    1137How to Make Honeycomb Coils  JP  Tube Pocket Radios Translated from the Japanese  [In Japanese. English here] 1[-]Construction HintsCoil Winding
    1138Einbereichs-Super - Spulensatzes  DE  Jogis Roehrenbude In German. Looks like an input filter of some sort.  [In German. English here] 9[-]Construction HintsCoil Winding
    1139Variometer  IT  Le Radio de Sophie In Italian. Build your own!  [In Italian. English here] 4[-]Construction HintsCoil Winding
    1140Coil winders: complex and simple.  US  K5BCQ Especially note the tips at the bottom of the page. I like the idea of feeding the wire over beeswax to give stick". 1[-]Construction HintsCoil Winding
    1141Coils; etc.  DE  Trommeltier Tables; math; pictures; etc. of typical coil values  [In German. English here] 1[-]Construction HintsCoil Winding
    1142Coils for Direct Conversion Receivers  DE  Trommeltier Types of antenna coils; troubleshooting; etc.  [In German. English here] 1[-]Construction HintsCoil Winding
    1143Homemade SuperHet Coil  JP  NGC's Soldering Very professional looking coil made from everyday materials  [In Japanese. English here] 1[-]Construction HintsCoil Winding
    1144Helmut's Trafowickelmaschine  DE  Jogis Roehrenbude “Helmut's Transformer Winding Machine”.  [In German. English here] 1[-]Construction HintsCoil Winding
    1145HF-Spulen Selbst Wickeln  DE  Franzis.DE “HF-Coil Self Winding”. A couple of approaches with photos  [In German. English here] 1[-]Construction HintsCoil Winding
    1146Coil winder  US  Dipsey Dumpster Looks like it can do universal winding, sort of (see pictures). 1[-]Construction HintsCoil Winding
    1147Winding Transformers  US  T Williams Pictures and descriptions 1[-]Construction HintsCoil Winding
    1148Roll-Your_Own All-Wave Three-Circuit Tuner  US  Crystal Radio Make your own tapped variometer 0[-]Construction HintsCoil Winding
    1149How to Wind an Antenna Coil or RF Coil  US  Fun With Tubes Always good to see different ways to wind coils; they scare a lot of people but shouldn't. 1[-]Construction HintsCoil Winding
    1150How to Wind an RF Interstage Coil  US  Fun With Tubes This one always frightened me. Now they're fun. 1[-]Construction HintsCoil Winding
    1151How to Wind an Oscillator Coil  US  Fun With Tubes Another scary one demystified. 1[-]Construction HintsCoil Winding
    1152HF-Spulen wickeln  DE  B Kainka HF Coil winding"  [In German. English here] 0[-]Construction HintsCoil Winding
    1153Gingery Universal Coil Winder  US  Big Nick's COOL 3.5 MB VIDEO! See third row of pictures on the right. 1[-]Construction HintsCoil Winding
    1154Spulenaggregate   DE  Erinacom “Coils”. Various parts fabricated at home: main coil, MW-coil on sewing machine bobbin, ferrite antenna, etc.  [In German. English here] 1[-]Construction HintsCoils
    1155Homemade SuperHet Coil  JP  JA9TTT From Japanese. Lots of pictures, charts, advice, etc. And really nice looking coils  [In Japanese. English here] 1[-]Construction HintsCoils
    1156Connecting your radio to your PC  US  N1KGH It seemed so simple; and it is; except the potential for stray frequencies. 5[-]Construction HintsComputer Interface
    1157Thermo-Fan  AU  Elliot Sound [Click to Project 42 from projects page.] Temperature sensor turns on 12V computer fan when temperature reaches a certain level. 12[-]Construction HintsCooling
    1158Crystal buffer stage  US  KA1UNW Recommendation allows use of much cheaper crystals. I like the idea of putting new (small) crystals into old FT-241 holders. 1[-]Construction HintsCrystal Buffer
    1159Dave's Crystal Grinding Page  US  WA4QAL Make your own crystals! (Or at least modify cheap out-of-band ones) 1[-]Construction HintsCrystal Grinding
    1160Detektoren, Koppler und Spulen   DE  Jogis Roehrenbude “Detectors, Couplers, Coils”. I've never seen so many different approaches to the crystal holder.  [In German. English here] 1[-]Construction HintsCrystal Holders
    1161Crystal Grinding Hints and Kinks  US  SubDevo Someday when I have a lot of free time I'll try this 0[-]Construction HintsCrystal detector
    1162Quick and Dirty Dummy Load  US  N0SS PDF File. Not so dirty. Uses monster Heat Sink and power resistors. 3[-]Construction HintsDummy Load
    1163QRP Dummy Load  US  N0SS PDF File. A couple of resistors. 5[-]Construction HintsDummy Load
    1164Homemade Earphone  US  Tom Kipgen's No schematic or drawings, but you can kind of tell what was required. Good jumping off point for inspired inventors. 5[-]Construction HintsEarphone
    1165Electrocution and How to Avoid It  AU  Elliot Sound [Scroll down articles page to article on Electrocution]. Very important. 1[-]Construction HintsElectrocution
    1166Build Your Own Heatsink  AU  Elliot Sound [Scroll down articles page to article on Build Your Own Heatsink]. 1[-]Construction HintsElectrocution
    1167Tutorial on Electolytic Capacitors  DK  Hans Egebo Good review of the essentials, particular what will harm them, what their values are, etc. 1[-]Construction HintsElectrolytics
    1168Strategies for Replacing Electrolytic Capacitors  US  Tim Reese's Different approaches: reforming, on-chassis, under-chassis, etc. 1[-]Construction HintsElectrolytics
    1169Cabinet From Aluminum Angle Stock  UK  Hans Summers A cheap and easy alternative to full sheet metal chassis construction. 1[-]Construction HintsEnclosure
    1170The Radio Restorer's Workshop  DK  Hans Egebo Describes the tools and instruments you should have, sorted into essential, nice to have, useless, etc. 1[-]Construction HintsEquipment
    1171KL4-E Ersatz Rohre  DE  Roehrenbastler “Fake KL4 Tube”  [In German. English here] 1KL4Construction HintsErsatz Tube
    1172Exray's Radio LL Super Baby Restoration   US  Spark Bench Lots of good parts fabrication on this page, with pictures: tubes, transformers, coils, etc. 1[-]Construction HintsErsatz Tube
    1173A Short Guide to Harmonic Filters for QRP Transmitter Output  UK  G QRP Good reference for quick jobs 0[-]Construction HintsFilters
    1174How to Blow Glass  US  Teralab Excellent introduction to scientific glass blowing 1[-]Construction HintsGlass-Blowing Tubes
    1175Vergolden  DE  Pauls Roehren “Goldplating” for contacts, parts, etc.  [In German. English here] 1[-]Construction HintsGoldplating
    1176Grounding Systems for Ham Radio  US  Tech Bench Elmers Always had me mystified 0[-]Construction HintsGrounding
    1177Star Grounding  US  Aiken Amps Tutorial on grounding 0[-]Construction HintsGrounding
    1178Grounding Issues for Hams  US  AM Window Discusses different types of grounds and how to get them. 0[-]Construction HintsGrounding
    1179Hum Prevention  NL  VT52 Classic checklist of what to look for and what to do 1[-]Construction HintsHum Prevention
    1180Bypassing Defective Interstage and IF Transformers  UK  Vintage Components Worth an experiment on a rainy afternoon 0[-]Construction HintsIF Transformer
    1181DIY IF Transformer  US  Radio Board Ferrite beads melted into plastic rod. Interesting approach. 1[-]Construction HintsIF Transformer
    1182Homebrew IF transformer  US  KA1UNW What's that one of the right? Nice photo at 1[-]Construction HintsIF Transformer
    1183DIY IF Cans for Tube Projects  SE  Harry's Homebrew Appears to be simple; and very nice looking. 1[-]Construction HintsIF Transformer
    1184IFT Coil  JP  Miyoshi “For 6A7”, but obviously modifiable  [In Japanese. English here] -[-]Construction HintsIF Transformers
    1185Homebrew IF Transformers - Another Approach.  JP  Portable From Japanese. Scroll to the middle and take a look at the homemade version.  [In Japanese. English here] 7[-]Construction HintsIF Transformers
    1186Using Transistorized IF Transformers for Tubes  JP  JA9TTT From Japanese. Not sure if I follow what he's doing here.  [In Japanese. English here] 1[-]Construction HintsIF Transformers
    1187QRP Common Low-Pass Filter Values  US  KA1UNW Quick chart. Build a bunch and salt them away. Nice photo at 1[-]Construction HintsLow-Pass Filters
    1188Homemade Bending Brake  CA  Junkyard Projects For those metal chasses . . . 10[-]Construction HintsMetal Brake
    1189Using Power Transformers for Modulation  US  AM Window Multipage article. 15[-]Construction HintsModulation
    1190Are Oscilloscopes Necessary  US  Electronic Peasant Yes. Many times yes. 1[-]Construction HintsOscilloscopes
    1191Output Transformer Design and Winding  US  Geofex Very methodical; by the numbers; approach 1[-]Construction HintsOutput Transformer
    1192Determining the Impedance Ratio of an Output Transformer  US  Radio Remembered Walks through the theory as well 2[-]Construction HintsOutput Transformers
    1193How I make PC Boards  US  N0SS PDF File. Not me; him (N0SS) 1[-]Construction HintsPC Etching
    1194PC Board Fabrication with Laser Printer  US  Tom Gootee Another one to try on a rainy day 0[-]Construction HintsPCB Etching
    1195Making PCB's Easily  SE  Harry's Homebrew Various methods 1[-]Construction HintsPCB Etching
    1196Foolproof Phototransfer onto PCB's  US  5 Bears Research Looks like the easiest way to make pinted cicuit boards. 1[-]Construction HintsPCB Etching
    1197Cutting Tool for Ugly Style PCB  UK  G QRP Just get out the file and shape the tip of a wood drill bit 1[-]Construction HintsPCB Tool
    1198Custom Meter Faces  US  KR6LP Apparently, you can separate paper from metal by spraying some freezing agent on it 1[-]Construction HintsPanel Meters
    1199Cross-Tabulation list (parts; tubes, etc.)  US  KA1UNW Quick identification tables of parts. Excellent; we need more of these. 1[-]Construction HintsParts Identification
    1200Better Way to Connect Pentode as Triode  US  T-Line Speakers There is some deep-thinking theory going on here. I'll have to spend some time with pencil and slide rule to really get it, but I'd like to try. 1[-]Construction HintsPentode-As-Triode
    1201A Better Log Potentiometer  AU  Elliot Sound [Click to Project 1 from projects page.] Apparently, the “log” pots you buy are really two linear pots. This simple circuit creates a better approximation of log. 2[-]Construction HintsPotentiometer
    1202Pots for Pennypinchers! Make Your Own Stepped Attenuators  MY  DIY Paradise Stick a whole bunch of resistors on a rotary switch; better audio than normal potentiometer 0[-]Construction HintsPotentiometers
    1203Output vs. Dissipation Limits  US  KA1UNW Helpful table for different modes; etc. 1[-]Construction HintsPower Dissipation
    1204DIY Series Power Transformers  US  Jon Tirone Hints on creating specific values of power transformers by hooking up smaller ones in series. 2[-]Construction HintsPower Transformers
    1205How to Identify Power Transformer Windings  US  Radio Remembered By color and resistance measurements 1[-]Construction HintsPower Transformers
    1206Easy DIY Method for Making PCB's  AU  VK5CU Good explanation with step-by-step photos of a method using transparancies printed on a laser printer. 1[-]Construction HintsPrinted Circuit Boards
    1207Das Geheimnis der blauen Folie Testplatinen mit PCB-Transferfolie   DE  Michael Gaedtke “PCB Fabrication with Blue Foil” (I think). Very detailed photos, etc.  [In German. English here] 1[-]Construction HintsPrinted Circuit Boards
    1208PCB Using Baked Bean Cans  UK  Hans Summers Sounds odd, but read the article; if you dont' care what something looks like it a great solution for cheap/quick construction 1[-]Construction HintsPrinted Circuit Boards
    1209Homebrew Audiophile Resistor  NL  DHT Rob Just have to have 183 ohms? A DIY resistor! Who can resist?  [In Dutch. English here] 1[-]Construction HintsResistors
    1210Rook Coil Winding for Radios  US  Rook Coils For crystal radios, mostly 1[-]Construction HintsRook Coils
    1211SMD Test Tweezers  US  DX Zone Good idea; and looks simple 1[-]Construction HintsSMD Work
    1212SMD Introduction for hobbyists  US  DX Zone From 2003 issue of CQ magazine 1[-]Construction HintsSMD Work
    1213TubePad 5.0  US  WD4NKA By far the easiest way to make schematics. I did my first schematic within 3 minutes of downloading. It's just a collection of bmp files to be put together in MS Paint. 1[-]Construction HintsSchematic Editor
    1214A Cheap Sheet-Metal Bender  BR  Teoria Pardon me if I've mistranslated; but the pictures tell you all you need to know.  [In Portugese. English here] 2[-]Construction HintsSheet Metal Bending
    1215Transmitter Signal Cleanup  US  Antique Wireless A collection of hints for fixing common signal problems. 0[-]Construction HintsSignal Enhancement
    1216The Technology of Soldering  US  Technology Interface Interesting discussion; including how things are done commerically; and including a bibligoraphy 1[-]Construction HintsSoldering
    1217A Surface Mount Soldering Iron  US  Engadget Buld your own. 1[-]Construction HintsSoldering
    1218Soldering Tip Cleaning w/o Heat Loss  US  N0SS PDF File. Uses kitchen scrungie" 1[-]Construction HintsSoldering
    1219Soldering Without Tears  US  Peebles Originals Magazine article with more how-to 1[-]Construction HintsSoldering
    1220How to Unsolder and Recover Electronic Parts  IT  IZ7ATH Using a hot-air setup; etc.  [In Italian. English here] 1[-]Construction HintsSoldering
    122110-page SMD Soldering Tutorial  US  Spark Fun Scroll down a bit. Has a very encouraging video demonstration 1[-]Construction HintsSoldering
    1222Information on Space Charge Tubes and Theory  US  Jeff Duntemann Actually this is a fun page. 0[-]Construction HintsSpace Charge Tubes
    1223Reusable Spider Coil Form  DE  Crystal Radio Net Uses a cut up CD and a large bolt/nut arrangement. Low tech and easy  [In German. English here] 1[-]Construction HintsSpider Coils
    1224Gollum's Honeycomb Coil  DE  Old Radio World Instructions and pictures for building a form and winding  [In German. English here] 1[-]Construction HintsSpider Coils
    1225Spider Coils  US  Dave Schmarder All the construction hints, mathematics, explanations, etc. 1[-]Construction HintsSpider Coils
    1226Homebrew stepped attenuator.  NL  DHT Rob For audiophiles who want the best potentiometer"  [In Dutch. English here] 1[-]Construction HintsStepped Attenuator
    1227Minimal Toolset for Homebrewersna  VE2ESE I like the reducto: a soldering iron and nail clippers. 1[-]Construction HintsTools
    1228UNKNOWN PLATE TRANSFORMER TEST  US  W2DTC W2DTC finds a 200 pound mystery transformer and wants to know all the specs. 2[-]Construction HintsTransformer Testing
    1229Rewinding Transformers  US  Tech DIY I've tried this, and it works 1[-]Construction HintsTransformer Winding
    1230Homebrew Audio Transformer  US  Tom Kipgen's Second project on page. No schematic or drawings, but you can kind of tell what was required. 3[-]Construction HintsTransformer
    1231Power transformers as output transformers  DE  B Kainka Discussion of saturation and other effects to consider. Circuit for measuring the effects is given  [In German. English here] 6[-]Construction HintsTransformer
    1232Berechnen und Wickeln eines Hi-FI-Gegentakt-Übertragers   DE  Jogis Roehrenbude “Design and Build a Hi-fi Output Transformer”. Page concentrates on push-pull transformer for EL84.  [In German. English here] 1[-]Construction HintsTransformer
    1233Grundlagen zum Wickeln von Transformatoren   DE  Jogis Roehrenbude “Theory of Self-wound Transformers”. Lots of math, plans, directions, tables of values, etc.  [In German. English here] 1[-]Construction HintsTransformer
    1234Straight-Core Transformer  US  Tesla Coil Mail Home-made transformer approach from the 1920's. I wonder what the efficiency of such a thing would be. 1[-]Construction HintsTransformer
    1235Ein Ubertrager für Bändchen-Lautsprecher   DE  Michael Gaedtke “A Transformer for the Ribbon Speaker”. Photos, plans, math, etc. for winding an output transformer  [In German. English here] 1[-]Construction HintsTransformer
    1236How to Build Transformers  US  Glowbugs Reference article on rolling your own. 1[-]Construction HintsTransformers
    1237Winding 455KHz I.F. Transformers  CA  Scorpio Rising See the other article on this subject for an easier way. 0[-]Construction HintsTransformers
    1238Winding Transformers; Part 2 (Chokes, etc.)  CA  Scorpio Rising Part II has file name windingtransformers" 0[-]Construction HintsTransformers
    1239Transformer Winding Jig  CA  Scorpio Rising This could be really useful. 0[-]Construction HintsTransformers
    1240Winding Transformers; Part 1 (Basic Power Transformers)  CA  Scorpio Rising Part II has file name windingchokes" 0[-]Construction HintsTransformers
    1241How to Choose an Audio Transformer  CN  VT4C One man's opinion 0[-]Construction HintsTransformers
    1242Filament Transformer for Audio Transformer Use  JP  JH2CLV From Japanese. Not sure if the translator got this right.  [In Japanese. English here] 1[-]Construction HintsTransformers
    1243Modify a TV Power Transformer to be a Modulation Transformer  US  AM Window If you're desparate. 0[-]Construction HintsTransformers
    1244Make Your Own IF Transformers  US  Fun With Tubes It's easier than you think". A general rule; I've found. 0[-]Construction HintsTransformers
    1245DIY MC Step up transformer  MY  Audio Hobbyist People who wind there own transformers are on a special plane. 1[-]Construction HintsTransformers
    1246DIY Output Transformer  MY  Audio Hobbyist More homemade transformers! Magic! 1[-]Construction HintsTransformers
    1247Trigger Coil  US  Don Klipstein's Basic how to" article; aimed at builders of strobe lights 1[-]Construction HintsTrigger Coil
    1248Troubleshooting Checklist  US  Handmade Electronics Great, detailed list 1[-]Construction HintsTroubleshooting
    1249Troubleshooting Chart  AU  Australian Vintage Here's a handy idea 0[-]Construction HintsTroubleshooting
    1250Triode Bias Supply (GRIDV)  DE  DL4MEA This circuit provides the grid bias voltage for any kind of triodes. It is equal to an adjustable zener diode with a switch-off capability."  [In German. English here] 25[-]Construction HintsTube Bias Control
    1251Tube Biasing  DK  Hans Egebo Danish (in English) tutorial on the mysteries of bias. 1[-]Construction HintsTube Biasing
    1252Roehrenkartons  DE  Pauls Roehren “Tube Boxes”. Make them yourself. Includes dimensions, gif files, etc.  [In German. English here] 1[-]Construction HintsTube Boxes
    1253DIY Tube Dampers  US  Harp Amps Why not? Looks like fun. 1[-]Construction HintsTube Dampers
    1254Fabrication D'une Lamp Triode  FR  Daily Motion Wonderful 17 minute video of a triode being handmade from start to finish. The piano background to the [silent] film is a great touch.  [In French. English here] 1[-]Construction HintsTube Fabrication
    1255Adaptors to put tubes on breadboards  DE  Jogis Roehrenbude Great ideas on how to connect tubes to breadboards  [In German. English here] 1[-]Construction HintsTube Sockets
    1256Creative tube substitutions  JP  Early Amateur Alternatives using semiconductors, miniature tubes, base replacements, etc.  [In Japanese. English here] -[-]Construction HintsTube Substitutions
    1257How to Select a Tube Tester  CA  Tone Lizard I learned a lot from this one. 0[-]Construction HintsTube Tester
    1258DIY Eyelet Boards  US  Harp Amps We should have a Cheap Eyelet Board Derby"; winner being who can build the cheapest with hobby shop parts. 1[-]Construction HintsTurret Boards
    1259Turret Lug Installation Tool  US  EL34 World How to install turret lugs, with various pictures and construction hints 1[-]Construction HintsTurret Lugs
    1260Condensatore variabile "a libro"   IT  Le Radio de Sophie “Variable Condensor”: Interesting approach using two large plates held at a “V” angle and adjusted.  [In Italian. English here] 1[-]Construction HintsVariable Capacitor
    1261Variable Amplifier Impedance Circuit  AU  Elliot Sound [Click to Project 56 from projects page.] “More of an article for experimenters”. 14[-]Construction HintsVariable Impedence Circuit
    1262Variometer  CZ  Dave Schmarder (Part of last project on page) Looks like a very do-able approach.  [In Czech. English here] 1[-]Construction HintsVariometer
    1263Four Foot Electronics Lab  US  QRP and SWL How to build a small footprint; high-quality home electronics workshop 1[-]Construction HintsWorkshop
    1264Common Electronic Parts  US  QRP and SWL How to stock your workshop or junkbox. 1[-]Construction HintsWorkshop
    1265Muirhead Coherer  NL  Arjan Muil How is this different? 5[-]Crystal RadioCoherer
    1266Bureau of Standards 1924 Crystal Set  US  HP Friedrich's Very complete plans for a very over-engineered set. 5[-]Crystal RadioCrystal Detector
    1267Crystal Superheterodyne!  US  HP Friedrich's See page 6 of this article (“The Crystal as a Generator and Amplifier”, 1924) 5[-]Crystal RadioCrystal Detector
    1268The CD-ROM Radio  US  HP Friedrich's Crystal radio built around a CR-ROM cylindar 5[-]Crystal RadioCrystal Detector
    1269Der ovale Franzosendetektor  DE  Jogis Roehrenbude In German. Oval Rench Detector". Full cabinet and coil construction instructions.  [In German. English here] 4[-]Crystal RadioCrystal Detector
    1270A Double-Slider Crystal Set  US  Old Radio Builder A “double slider” indicates that both the antenna and the other side of the tuning coil have their own sliders. 5[-]Crystal RadioCrystal Detector
    1271Another Very Nice Mysery Set  US  Old Radio Builder Crystal Set 5[-]Crystal RadioCrystal Detector
    1272The Mystery Crystal Set  US  Old Radio Builder One of the most beautiful set of pictures 5[-]Crystal RadioCrystal Detector
    1273Econoceanic Crystal All-Band  US  Tdufres “Honey, I need a new project . .” 7[-]Crystal RadioCrystal Detector
    1274Krystalontvangers  NL  PA2G Dutch crystal radio. Nice crystal housing.  [In Dutch. English here] 4[-]Crystal RadioCrystal Detector
    1275Japanese Crystal Radio  JP  Lhokusai Nice looking box with Japanese lettering.  [In Japanese. English here] 5[-]Crystal RadioCrystal Detector
    1276Foxhole radio  US  DJ Adamson But what about the headphones? Are they found in the typical foxhole? 5[-]Crystal RadioCrystal Detector
    1277Frog Leg Detector  US  Chesson “Le Detectueur Francais Cuisse de Grenouille” 5[-]Crystal RadioCrystal Detector
    1278Das Detektorradio  DE  B Kainka Crystal Radio  [In German. English here] 5[-]Crystal RadioCrystal Detector
    1279Razor-blade crystal radio  AU  Adventures Cybersound One to try with the cub scout troops. 5[-]Crystal RadioCrystal
    1280Mystery Crystal Set  AU  SE Queensland The winning entry of a club contest among 17 submissions 6[-]Crystal RadioDiode detector
    1281Mystery Crystal Set, Part 2  AU  SE Queensland The winning entry of a club contest among 17 submissions 6[-]Crystal RadioDiode detector
    1282Mystery Crystal Set, Part 32  AU  SE Queensland The winning entry of a club contest among 17 submissions 6[-]Crystal RadioDiode detector
    1283Crystal Radio with Speaker  NL  Crystal Radio EU Can you really drive a 6 inch 250 ohm speaker from a crystal set?  [In Dutch. English here] 4[-]Crystal RadioDiode detector
    1284Crystal Receiver with Bright Coils  NL  Crystal Radio EU Why would a builder use what appear to be copper strips instead of wire; at least in this incarnation  [In Dutch. English here] 22[-]Crystal RadioDiode detector
    1285Crystal Receiver with Large Loop Antenna  NL  Crystal Radio EU The coil is the antenna.  [In Dutch. English here] 8[-]Crystal RadioDiode detector
    1286Contest Quality Crystal Set  NL  Crystal Radio EU Interesting desing features. Three Schottky diodes in parallel are the detector.  [In Dutch. English here] 16[-]Crystal RadioDiode detector
    1287Max Radio  NL  Crystal Radio EU So easy a child could do; wait a minute  [In Dutch. English here] 7[-]Crystal RadioDiode detector
    1288Radio with ceramic resonator  NL  Crystal Radio EU Receiver can receive only one stattion  [In Dutch. English here] 9[-]Crystal RadioDiode detector
    1289One-Active-Device Crystal Radio  UK  Crystal Radio US Uses a FET as BFO for exalted carrier mode 14[-]Crystal RadioDiode detector
    1290MF102 BFO Crystal Set  UK  Crystal Radio US Second project on the page. Note the way a rack is used for variable coupling 13[-]Crystal RadioDiode detector
    1291The Brianodyne  UK  Crystal Radio US First project on the page 13[-]Crystal RadioDiode detector
    1292Regenerative Receiver with Ferrite Rods on Rack  UK  Crystal Radio US First project on page. Note the picture of the wave traps. Nice set. 10[-]Crystal RadioDiode detector
    1293Crystal radio DX-ing Hints  UK  VE7SL Walks through the various approaches to coupling, in particular. Very useful. 5[-]Crystal RadioDiode detector
    1294DX Crystal Radio  US  N4DKD Nice, clean components. 12[-]Crystal RadioDiode detector
    1295Crystal receiver using slug-tuned coils  DE  Old Radio World Side-by-side English and German, which is useful and fun  [In German. English here] 5[-]Crystal RadioDiode detector
    1296Crystal receiver construction project  DE  Old Radio World With links to component sourcs  [In German. English here] 4[-]Crystal RadioDiode detector
    1297Experimental Short-wave Mystery Crystal Radio  US  KC4IWT Different design ideas. 5[-]Crystal RadioDiode detector
    1298Un détecteur d'ondes radio  FR  F5ZV Simple diode-detector radio  [In French. English here] 3[-]Crystal RadioDiode detector
    1299High Sensitivity Crystal Radio Set  US  ARRL From QST, January 2007 5[-]Crystal RadioDiode detector
    1300Quick Receiver  SE  Harry's Homebrew A bit of a trick; in that you add a separate oscillator and amplifier 6[-]Crystal RadioDirect Conversion
    1301Crystal Radio with Box Antenna  AU  P. Parker Actually; the aerial is more of the resonant coil than an aerial. 4[-]Crystal RadioDirectional
    1302FM Crystal Receiver  NL  Crystal Radio EU Coil L1 is a 285 mm long copper tube, the outside diameter is 12 mm  [In Dutch. English here] 9[-]Crystal RadioFM Slope Detector
    1303DX receiver with two tuned circuits  NL  Crystal Radio EU Three separate sections: antenna tuner, detector units. Transporation  [In Dutch. English here] 14[-]Crystal RadioFM Slope Detector
    1304Short-Range FM Tuner and Pocket Radio  US  LTJ Designs Looks kind of rickety. 5[-]Crystal RadioFM Tuner
    1305FM Crystal Tuner  US  Vacumm Tubes Inc. Lot of plumbing to fabricate 4[-]Crystal RadioFM Tuner
    1306VHF/UHF RX/TX MONITOR  SE  Harry's Homebrew He says he's made 20 of these for different bands. How hard could it be? 5[-]Crystal RadioFM Tuner
    1307Crystal radio / nice coils  NL  PA2G Dutch site with nice-looking crystal holder and coils  [In Dutch. English here] 6[-]Crystal RadioGalena
    1308Crystal Scout  FR  Amatech Fench crystal radio from early 20th century  [In French. English here] 6[-]Crystal RadioGalena
    1309Experiment with 4 approaches to germanium detectors  JP  JK1MLY Full wave, half wave, bridge, etc. I like the way each is set up for easy switching.  [In Japanese. English here] 6[-]Crystal RadioGermanium
    1310Crystal Radios  DE  DL2XM Some very high-end crystal radios  [In German. English here] 5[-]Crystal RadioHigh End
    1311High Power Crystal Set  US  John G. Schatz, Jr. Uses voltage doubler, transformer to be able to drive a small speaker. 8[-]Crystal RadioHigh Power
    1312Receiver with Loop antenna  NL  Crystal Radio EU Interesting rustic construction of the 26x38 cm (10x15 in) loop  [In Dutch. English here] 4[-]Crystal RadioLoop Antenna
    1313Chrystadyne Receiver  FR  Allen's Site From the pages of radio archeaology. 4[-]Crystal RadioNon-Traditional
    1314Make anywhere ore radio.  JP  Radio Sammlung From Japanese. Good photos of parts made from objects around the house. Note the 100K resistor made from a wet toothpick.  [In Japanese. English here] 4[-]Crystal RadioOre
    1315Gegentakt Detektor  DE  Jogis Roehrenbude “Push-Pull Detector”.  [In German. English here] 9[-]Crystal RadioPush Pull
    1316Weitempfang Detektor  DE  Jogis Roehrenbude “DX Detector”.  [In German. English here] 11[-]Crystal RadioPush Pull
    1317Razor blade crystal radio  JP  Radio Sammlung From Japanese. Great idea for school project. Note all homebrew parts, including coil wound on a block of wood.  [In Japanese. English here] 4[-]Crystal RadioRazor Blade