Well, friends, I am back once again playing around with big fat tubes! It must be something in the water. But I do love those big old things and this 12 volt DC schematic from Dave is just the thing. It operates on a wall wart converter and does away with all the fuss with A, B and/or C batteries or with power supplies. Not only that but it is safe enough for kids....like me!
The tube is jacked up on brass stilts that pass down through the center of the tickler coil, the main coil and the primary coil all displayed in a clear acrylic tube. All the coils are honeycomb construction using magnet wire for each. The tickler is #30 wire with inductance at 9uH. The main coil is .024" wire with inductance at 255uH. The primary is gigantic .064" wire with inductance at 36uH.
Those coils work great and the entire broadcast band is tuned with a 365 mounted in the cabinet. If you look closely you'll notice a peep-hole that views the tuning dial made of an AOL disk which is run on a vernier drive I got from Dave. He sure has a lot of good goodies.
That cabinet and base are of solid mahogany as are the homemade knobs. Brass binding posts and knurled knobs are mount on the back of the cabinet for antenna and ground connections. I tend to run these sets through my computer speakers so that I can listen while I work on the next set. Therefore, the jack is located in the front below the center tuning knob.
Please e-mail me for price and availability. Order: #T-019