[Milsurplus] Hamvention Radio project

[Ray Fantini]

Looking to build up a mess of 3885 AM radio for Dayton (Xenia) next year, something a little different from the usual. Have my 1938 RCA Marine receiver and just picked up a box full of ARC-5/T-19 transmitters that have all been hacked and wanted to put this together with a Narco T-12MP power supply modulator to power both the receiver and transmitter. The Narco develops +175 volts for the receiver B+ with the receiver working well at this reduced voltage and drawing only a dozen or so mills with the entire system of the receiver and inverter drawing a little less than three amps at twelve volts during receive operation.  Hope to use the HV modulated output from the Narco that's around +330 volts along with its +175 volt output to run the T-19. Figure I don't need that much power and would be happy to have a couple watts assuming the modulator won't be able to provide that much modulation to begin with.
The big questions now are first, do I run one or the two 1625 tubes in the transmitter? Figure out of the half dozen or so that I just picked up can put together one transmitter for use with this receiver, all of them are in bad shape but being this will be a modified system for low power operation can get something together. Want to try to keep the circuit as close to original within reason but missing all the calibration crystals, ceramics and relays from all the transmitters that's going to be an issue. Don't know why but everyone had been modified for coaxial output and being in the field with running a short wire antenna the original ceramics would have been perfect.
Going to assume that I can run the oscillator (VT-137) from the +175 volt source, maybe use that for the G2 of the PA also and use the +330 modulated source for the PA Plate or I can modify the T-12MP to provide a clean +330 for the plate and then use its internal modulator for screen modulation of the PA (VT-136)? Remember the key here is I don't need lots of power. Three to five watts is plenty.
And the last issue is the stupid male sixteen pin plug on the Narco T-12 power supply modulator. It's the same size as an octal plug but has sixteen pins with a ring twelve pins on the outside and four pins in the center. I would prefer to find the matching sixteen pin socket to use on this power supply being a lot of stuff goes in and out thru it, not just B+ and power but also the microphone input, speaker cables and T/R control.
Looked on EBay but have not seen one yet.

Ray F/KA3EKH
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