[Boatanchors] Crystal calibrators for HAM use???

[Claudia & Reed Park]

William L Howard wrote:

> Tom B and I have been discussing the Czech R 11 sets and the fact that
> many of them are missing the crystal calibrators. I asked:
>
> OK, then, why are there so many sets missing them? Are they useful for
> >some other HAM radio application? It looked like it was a crystal
> >controlled oscillator, similar to some of the ones used with the WW II
> >German sets. Presumably it would be issued with a crystal useful for
> the
> >frequency of the set with which it was to be used.
>
> Tom replied:
> Hard to say why they are missing. It is a useful crystal oscillator.
> The crystal in the low
> frequency model is 25 Mhz.  I can't think of a real good use for that.

Unless the xtal is 25 Mhz and then it is divided down to 1 Mhz and 100 khz
and 25 khz which results in a very stable marker signal. It is now a common
thing to do but not sure when they started to do that. Even some of the AM
broadcast stations use a crystal higher than the desired operating frequency
then divide. CKCW (now off the air) was 1220 khz but used a crystal of 2440 khz
and a divide by two circuit.

Of course, I could be all wet also re xtal calibrators. I have used the one on
my
Mk III number 19 set with some of my old receivers to figure out where I was.

7 3
Reed   -   VE1NU

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Looking for information on Marconi SMR-3 and
Northern Electric R8119A receivers of WW 2.