ICOM-R71 Restoration
"I bought This R71A on eBay cheap because it didn't work. The Voltage Controlled Oscillator (VCO) trimmer capacitors in several Icom receivers tend to get dirty and drift. I turned them through a few times (most people replace them with a better quality trimmer), and adjusted them. Still working fine several years later."
Vacuum Tube Analyzer
"I guess I'm proudest of the tube analyzer, because it's mostly switching, which has always been difficult for me. Everything went from my brain to the prototype-- I couldn't make a schematic for it if I had to! Two years of thinking and plotting, and about three weeks of building. Due to the close quarters, I had one shot at it-- hence the colored wires."
Electroluminescent Receiver
"Thanks to David White for the most fun-filled and versatile kit I've ever assembled! I'll be building another this winter. I intend to use this as a model. It's the wide one, second from the bottom pic."
Indeed... If you're curious about the Amazing Electroluminescent Receiver, check out David White's ELR Website
Audio Amplifier / Power Supply / PreAmp Power Supply
"OK, the amp is a mod to a circuit I picked at random on the 'net. A single-ended circuit, I used four output tubes in parallel, which required output transformers with a primary impedance 1/4 that of one tube ie 1250 ohms instead of 5000. Then I decided to use the 6094 tubes, which were intended for ICBMs. They don't come better than that. The 6094s required a change in the bias, and because it's a self-biasing circuit, only required changing out one (cathode) resistor per tube. The power supplies I just threw together. They feature four 6X4 each, wired in a parallel full-wave arrangement which reduces power supply impedance. The chasses are just old filing trays from a defunct bank. If you haven't heard single-ended, you oughta. Project took two+ years. Most of that was planning and modifying."
"The preamp is a combo of two circuits found in the back of the RCA Tube Manuals. Simple, well-engineered, and clean. The power supply I just threw together."
Heathkit Active Crossover
"This is a near-clone of the famous Heathkit Active crossover, in stereo. Dual power supplies."
