Here's the front panel, bandset condenser at the upper left on the side, bandspread tuning via the National type B dial, regeneration at lower left and on-off at lower right:
I had to build the chassis. It's just galvanized sheet metal -- aluminum might look nicer. Top view with the lid off -- band selection by plug-in coils! I didn't have any simple-type grid-cap clips but the little brass coil spring works okay:
From below, you can see my efforts to "fine tune" the regeneration control with paralleled resistors. The original used a carbon-compression rheostat, an early multi-turn variable resistance, but I had to come up with a coarse setting:
Multiwire cable out the back to the batteries -- 3V "A" and a 45V, tapped at 22.5V "B." The detector is a type '32 screen-grid tube with two stages of audio from the '19 dual-triode in the back compartment.LATER: Here are the scans, of the photocopies I worked from back when I built it. I don't seem to have the first page and there's about a decade (110 issues) of RADIO to go through, so gimme a few. I used a different bandset condenser, detector plate audio-coupling choke and RFC -- his looks to be a Hammarlund.
Very typical of radios of the era. Many were likely built with what could be found or bartered.
ReplyDeleteTinplate was common, aluminum was not and not solderable as well.
Eck!
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ReplyDeleteBuilt one something in a steel minibox when Bluff City (Memphis) Electronics was out of aluminum. It ate all my drill bits and an octal socket chassis punch. Never did that again. One guy here (Phoenix) makes his from double-sided PC board now and is getting truly gorgeous results. A good sheet metal cutter (Harbor Freight) is about the only special tool.
ReplyDeleteNice Thoradsen choke. Very nice.