[Milsurplus] BC-611 power

[Richard Arland, W3OSS]

Hi John:

Thanks for the input. My thoughts were originally to have them make separate 
dc-to-dc converters for each radio, but then, after reading your post, I 
think that maybe a generic converter might be a better idea. One that would 
put out 1.5, 3, 6.3 & 12 V dc for filaments, various bias voltages and a 
selection of B+ outputs all from a single unit. SMD would be a definite 
option to keep things small. Anyway, more inputs are welcome. I will take 
these present them to Dave for his review.

Again, thanks guys.

73 Rich



| It's a relatively straight forward task. I roughed out a design for an
| inverter to run a WS 58 (Canadian, 6 to 9 MHz). It had a 555 as a clock
| running about 120 Hz, a flip-flop divide by two to ensure symmetry, a
| quad gate to ensure the oscillator was running and protect the output
| FETs, a 24 V CT Radio Shack filament transformer run backwards and a
| bridge and single stage, full wave, doubler (the 58 set needs both 90
| and 180 VDC). There was also a small full wave tripler off the primary
| side of the transformer to make a -21 V C bias. I used a small reed
| relay, rewound with heavy wire, in the filament line so the inverter
| would come start when the set was switched on.
|
| The whole thing required 8 C or D cells (2 for filaments, 6 for HT) and
| I figured 30 to 40 hours per battery set with Alkalines.
|
| I never got to packaging it for the set, but I know it worked.
|
| -John