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Homemade scope clock using a DG7 tube & a Microchip PIC16F876 - I was lucky to purcase two used but working DG7 tubes and a transformator cheap, one from Mullard and one from Phillips. Other CRT Cathode Ray Tube types can be used, you can even rip one from an old and maybe dead oscilloscope __ Designed by Thomas Scherrer OZ2CPU
Hybrid vacuum tube/solid-state audio power Amplifier - 08/11/14 EDN Design Ideas: An audio power amp design that combines vacuum tube input circuitry with solid-state output and feedback components. Design by Craig D. Merz
IT-coupled 6C45P-6B4G PP Amplifier - Fixed bias on both stages. The amp is based on Ralph Power's simple iT-coupled PP amp. However, being a Fixed Bias Believer, I converted both stages to fixed bias. Output stage uses a conventional power supply for biasing; first stage, 6C45P into. __ Contact klausmobile @ yahoo.Com
Klauskorrektor I - The first phono stage __ Contact klausmobile @ yahoo.Com
Klausmobile Tube Tester - The tester is an entirely analog device controlled by a PCI bus industrial DAC/ADC card. As built, it enabling curve-tracing of small single and dual triodes with indirect heating. Dual triodes can be tested each side separately or both sides in parallel. Full tests of pentodes are possible with an external screen grid supply. The design __ Contact klausmobile @ yahoo.Com
Liquidator Tube Phaser/Chorus Effect - This project involves the conversion of a Hammond AO-47 organ vibrato unit into a 4 phase guitar/music phaser/chorus box. The individual phase signals can be mixed for a wide variety of sounds. The Liquidator name comes from the liquidy sounds that the device creates, it wiggles the audio all around. Used Hammond vibrato units can often be purchased for little money on eBay and provide the majority of the circuitry for this device. The Hammond AO-41 box can also be used for this project, it has a similar phaser circuit and one extra 7 pin tube socket. Here is the Original Hammond AO-47 Schematic for reference. __ Designed by G. Forrest Cook
Little Guitar Amp - I built this little guitar amp for my brother, Rich, a while back. Originally it was sort of a Fender "Champ" copy with a 12AX7 front end. I recently converted it to use a single EF86 pentode, instead. I like it much better this way. The amp chassis fits into a small maple open-back box with a single 10" speaker. Rich built the box __ Designed by Bob Danielak
Low Power Single-Ended 6SN7 Amp - I built this little amp for my computer at work. it sounds pretty darn good thru some old speakers from an Emerson tube console. At <1/2 Watt it is STiLL too loud for my office. __ Designed by Bob Danielak
Low Power Single-Ended 6SN7 Amp power supply - This is the power supply for the 6SN7 Amp __ Designed by Bob Danielak
Magic Eye Tube Wavemeter - This project uses a "magic eye" indicator tube as the meter element of a general purpose wavemeter. The wave meter can be used to monitor the actual radiated power from a ham radio station. This can be very helpful when adjusting an antenna tuner. The wave meter can also be used as an audio level indicator (vu meter). The project can provide some nice "eye candy" for your ham radio shack. The wave meter covers five different frequency ranges spanning 3.1 Mhz to 33 Mhz, covering the 80 Meter through 10 Meter amateur radio bands. A switching arrangement is used for selecting different coils, coil taps and capacitance ranges for the various frequency spans. A 3P5T range switch was used since I had it in my parts collection. A 3P3T switch could cover the same frequency range. The second and fourth ranges provide finer tuning, but are redundant __ Designed by G. Forrest Cook
Mammoth I - Mamont (aka Mammoth, Mamoet, Mammut) power amp was built around Atma-Sphere M-60 design. Atma-Sphere site had enough info on the amp schematic and after-market mods and tweaks. Output tubes (8 per channel __ Contact klausmobile @ yahoo.Com
Miniscope-Simple Circuit all-valve 1-Inch CRT oscilloscope - This beautiful homemade oscilloscope is the craftmanship of the late Len Hall G3iGI and was kindly given to me by Graham Firth G3MFJ at the 2008 G-QRP-club mini-convention. Graham has seen my own 1-inch oscilloscope project (also pictured, far right) and knew I'dbe interested in it! Another similar project (right) is by Andy G4OEP.. __ Designed by Hans Summers
Nixie Clock - Hand drawn schematic only__
Nixie Clock PIC16F876 - Schematic only__
Nixie-Clock using Neon Lamps to form Logic Gates - The above shows my home-built digital clock. it uses Nixie-tubes for readout. in contrast to most other nixie-clocks being built these days, my clock does not use any transistor or IC for driving the tubes. instead, the driving logic is built from neon lamps, together with resistors, capacitors and silicon diodes. __ Contact: pa3fwm @ amsat.org
Obtain a Gain Of 450 From One Vacuum Tube - 06/20/12 EDN Design Ideas: Combine sand (silicon) with vacuum tube technology to get the best of both. A direct-conversion radio receiver required an audio gain of 450 from a pentode vacuum tube. A pentode has a high transconductance—that is, the ratio of the change in plate current to the change of the control grid voltage that caused it. To get high gain, however, it needs a high load impedance. RF applications with pentodes often used LC-tuned circuits in their plate loads in which the impedance at resonance and, therefore, the gain is high. it is typically impossible to implement a high load impedance using an untuned circuit because of the dc requirements of the tube. Design by Lyle Russell Williams, St Charles, MO
OCTAL Phono Preamp - This preamp design started out as a conventional three stage cascade with feedback RiAA equalization. I decided on 6SL7's running into 6SN7's. I figured it would be a good match (electrically and asthetically) for my 2A3 Amp. After thinking it through I thought I might just try passive RiAA. (Even a better match - no feedback! ! !) I noticed a neat RiAA preamp circuit in the back of the RCA Tube Manual RC-19 that used a single 7025 per channel __ Designed by Bob Danielak
One Valve CW transmitter - This transmitter was first constructed in 1987 and provided the author with his first 'real' rig, capable of distances of more than about 100 metres. it performed better than expected, with 250km contacts being commonplace and 2500km being occasionally possible. __ Designed by Peter Parker
Oscilloscope as an Image Viewer - Cathode ray oscilloscope (CRO) is a versatile laboratory instrument which is used to display, measure and analyse electrical signals. it is nothing but a fast x-y plotter that displays an input...__ Electronics Projects for You
Oscilloscope CRT Clock - Apparently i'm in the shameful habit of making clocks in my spare time. First it was the Weston voltmeter clock, and then "Nixie 1, " a single-digit Nixie clock. Since soon after finishing the latter, I've been daydreaming about making a clock out of an electrostatic deflection CRT—the kind of thing you find in an oscilloscope. Given that I've just come across some free time in the form of Christmas vacation 2005, I decided to make one of my own __ Designed by © 2007 Riad S. Wahby
Pattern generator based on an Atmel ATtiny2313 running at 20MHz - This is a pattern generator with 13 images and 1KHZ tone, good for testing LCD TV’s, projectors and cathode ray tube TV’s. The project is based on ATtiny2313 running at 20MHZ. The horizontal frequency is 15625HZ and the vertical frequency is 50HZ (Europe standard). __ AVR Projects Dim
Phono Preamp valve - tube design__
Power supply for a car tube Amplifier - To minimize heat loss on any transistor, I use two pass FETs. in the car, input voltage is either 11.5-12.5V (engine off) or 13.5-14.5V (engine on). in the first case, T1 and T2 are fully ON, no need for heatsink. in the second case - T1 is OFF, T2 ON, all voltage and power excess is released across R5, no heatsink necessary for FETs. However, when input is in between (1314V) - T1, in a linear regulator mode, may dissipate up to 3W (for a 3A load current). __ Contact Klausmobile Tube Tester Files
Power Supply for a SE 300B Amp - Schematic for the power supply__
Power Supply for Vacuum Tube Experiments - This project is a general purpose power supply for small vacuum tube projects. it can be used for prototyping low power tube devices with one or more vacuum tubes. it is also useful for powering QRP (low power) transmitters, audio preamps and other small tube circuits. __ Designed by © G. Forrest Cook
Pure a Class Tube Amp - 15W pure A Class and Push Pull __ Designed by puechmor @ mygale.org
Push Pull 24 Watt a Class Amplifier - Schematic only, circuit description is not included __ Designed by Darrell Whitfield
Push-Pull 5687 Amp - This stereo amp will give you 4-8W/ch of zero feedback triode power for less than a pair of Chinese 300B's if you know where to shop. For those of you who are unfamiliar with this lil' tube here's the poop. The 5687 is a 9-pin miniature twin triode (a la 12ax7, 12au7, etc - but with different pin-out). its specs are quite interesting __ Designed by Robert Danielak
Push-Pull 6L6 GUITAR Amp - The schematic for the guitar amp __ Designed by Robert Danielak
Push-Pull 6Y6 Stereo Amp - This is a pretty straightforward PP amp design except for the unique positive feedback from the phase-splitter cathode to input stage cathode.12 Volt input tubes were used because this amp is going to be used in my CAR (with a 250V switching power supply for B+). More info will be added as time permits. __ Designed by Robert Danielak
Pushpull Class a 2a3 Stereo Amp - The input stage is comprised of a both halves of a 6SL7 octal dual hi-mu triode in a differential amp configuration with a 1ma constant current cathode load. i'm using field-effect (constant-current) diodes for simplicity. the diff amp approach was chosen for good power supply rejection, ease of balancing, good gain, and ease of application of *feedback*, if desired (hey, I like to keep an open mind). it also takes care of phase-splitting right up front. Note: I'vereturned the constant current diode cathode to -9V instead of ground in order to avoid the non-linearities about the pinch-off region (Vpo ~= 1.5V) __ Designed by Bob. D. @ robert.m.danielak @ lmco.com
Pushpull Class a Amp using Type 5687 Dual Triodes - This stereo amp will give you 4-8W/ch of zero feedback triode power for less than a pair of Chinese 300B's if you know where to shop. For those of you who are unfamiliar with this lil' tube here's the poop. The 5687 is a 9-pin miniature twin triode (a la 12ax7, 12au7, etc - but with different pin-out). its specs are quite interesting __ Designed by Bob. D. @ robert.m.danielak @ lmco.com
RGB pattern generator based on an Atmel ATtiny2313 running at 20MHz - This is a pattern generator with 13 images and 1KHZ tone, good for testing LCD TV’s, projectors and cathode ray tube TV’s. The project is based on ATtiny2313 running at 20MHZ. The horizontal frequency is 15625HZ and the vertical frequency is 50HZ (Europe standard). __ AVR Projects Dim |
