[Milsurplus] TCK lower compartment

[Kenneth G. Gordon]

On 29 Apr 2017 at 8:30, Steve kd3ht wrote:

>     Mine TCK6 looks the same rob.
>     interested in seeing the picture of the TCK4 and how a supply is shoehorned in there. 
>      
>     Steve, kd3ht

Hi, Steve.

FIrst of all, Rob is correct: my modulator is gone, and the power supply is installed there 
instead.

Secondly, from the way this was done, I hardly think it was "shoehorned" in there. The entire 
installation LOOKS commercially done, right down to the chassis and how it is mounted in 
there, complete with very professionally-done lacing of all the wires, and forming them at 
right-angles. I have never learned how to lace cables, although my favorite Elmer, W7CJB, 
used to do it regularly. I have always tried to make anything I have built look commercially 
done, but this job is particularly nice.

I would really like to know something of the history of this transmitter, but unfortunately, 
there is simply no way I can find out anything about it.

What is interesting to me is that the power supply was very carefully integrated into the 
transmitter's original control circuitry, complete with "High", "Low" and "Tune" functions 
included, plus overload relays, and timers. It is really very well done.

I am looking forward (not particularly happily) to tracing out the circuit, but at this point, I 
suspect that 1) the power supply is a "standard" although old-fashioned circuit, and 2) the 
modifications for RTTY are, I suspect, a "shift-pot" addition to the VFO circuitry. I used the 
"shift-pot" addition to a Heathkit VF-1 many years ago to operate RTTY. I used the VF-1 to 
drive a modified and upgraded DX-35, which then drove a modified BC-610 to a kw of 
RTTY. It worked very well.

It would make sense to me that the AM circuitry was determined to be pretty much useless 
at that time. I suspect that the transmitter was used primarily for MARS use, and at that time 
(shortly after WWII) MARS was changing over from AM to SSB, so 100 watts of 
grid-modulated AM from a 300 lb plus transmitter was not an efficient use of it.

Still, I really like all the knobs and dials and meters. It will be a very impressive and useful 
addtion to my shack. What is not to like about a 300 lb plus transmitter almost 5 feet tall 
sitting majestically in a prominent part of the station and being operated regularly? :-)

Ken W7EKB

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