[Collins] KWS-1 Crystal problem

[Ray, W2EC]

"Dx. Gxxxxx X. Jxxxxxx, exxxxxxxx exxxxxxx" wrote:
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Further on this problem:

First off, I have received the crystals back from JAN after their
testing and I am still unable to get them to function.

The one thing I haven't tried yet is swapping the oscillator tube as
several suggested, which I will try tonight, however what I hadn't
mentioned previously is that at the very start I had swapped the
original 12.5mc and 13.0mc from the 10 LO position and 10 HI positions
and peaked them up to see what would happen. Sure enough, I was able to
get the 12.5mc crystal to oscillate correctly in the 10 HI position
(with the appropriate change in dial frequency of course) and with the
same 1.1 volts of drive I got when it was located in the 10 LO band
switch position, and the 13.0 crystal oscillated in the 10 LO position
position at the same .1 volt level I achieved when it was in its
original 10 HI position. In swapping crystals, it only required a couple
turns of each plate inductor to get the circuit to peak with the
alternate crystal. Again, neither new JAN crystal would kick off at all
in either crystal position.

The fact that the drive voltages follow the crystals, kinda gives me a
warm feeling that the circuit components themselves are pretty close and
is what led me to my original conclusion that it was the 13.0mc crystal
itself that was "weak". 

Even if the circuit components were out of spec, I would at least expect
the new crystals should function somewhat since the original crystals
seem to work. 

Still searching for clues.......

73, Ray  W2EC