[Milsurplus] BC-654 experiences

[Richard]

The TBX works well for net fixed frequency use, but for general tuning 
those thumb wheels are a bear and you never know exactly where you are.

The TBW is interesting.  It was designed to be carried ashore in a small 
boat by several men.  Three packages; mf and hf transmitters, and 
modulator & power supply.  It runs on 120 volts 800 cycles to keep the 
weight down.  The power supply & modulator weighs 68 pounds, and would 
be about 240 pounds if on 60 cycles.  Making a 60 cycle supply will be a 
challenge because keying is a combination of primary and grid block, 
which works well at 800 cycles.  I use an aircraft "Screaming Mimi" 
inverter in a box for noise reduction.  (28 volts, 55 amps key-down)  
It's a joy to use - nearly 200 Watts output.

The BC-223 is a nice small transmitter - uses 801A tubes which are 
expensive now.  They used to be cheap, 25 cents each because no-one 
wanted them.   Once tuned up don't touch anything because changing 
loading or amplifier tuning will pull the oscillator and the other guy 
will lose you.  Well, you can use crystal control...

Richard, AA1P

On 4/7/19 2:49 AM, Hubert Miller wrote:
> I have not used a BC-654, altho I own several, but I did get a chance to see one used close up, one with the full vehicle setup, and it sounded great.
> I have always considered the limited 80 meter frequency range to be a major drawback.
> I do have one which has the rec dial relabeled down to something like 3000 kcs, but I have never tried it out. Before I sell it, I should have a look to
> see how smartly or dumbly this was executed, and maybe try at least the receiver also.
> At one time I was thinking about trimming the upper reach of 5850 kcs. to about 7400 kcs. I have actually spent some time looking at the tuned
> circuit values. But - this would require slightly trimming the inductances also => which requires removing covers etc. => plus doing a bunch of math
> => and that all is more work than I want to take on anymore.
>
> I second Robert Downs's opinion of the schematic and I'm happy to hear someone else thinks it's nuts. Maybe as a reduced level of project I will
> redraw those schematics in what I consider to be readily understandable, sane manner. Right after I do the schematics for the antenna switching
> for the GRC-9 and BC-1306.
>
> Because of the BC-654's limited frequency range, I can't recommend it to anyone who wants more usefulness than a limited frequency range of
> 80 meter AM.
>
> The BC-1209 I have does cover the band 2200 - 4400 kcs. but oddly, has a single 2E22 which it drives much harder than the 307A pair in the -654,
> plus this set only has one IF to the BC-654's 2 IFs.  And it has a meter rectifier tube. Odd indeed.
>
> Many years back I spoke with someone who had used the BC-654 in Europe WWII.  He told me at times they had two men cranking the gen, one
> on each crank. I believe it. I read somewhere where the handcranking process was like riding a bike, and all of a sudden you're pumping up a steep
> hill.
>
> The GRC-9 is a very practical radio compared to this.
> -Hue
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