[Collins] WARC XTALS for KWM-2A

[Dr. Gerald N. Johnson]

The standard crystals would be:
13.155 Mhz for 10 to 10.2, and would give 10 MHz WWV in the bargain.
21.155/2 = 10.5775 MHz for 18 giving 18.0 to 18.2 MHz.
37.955/2 = 13.9775 MHz for 24 giving 24.8 to 25.0 MHz.
These are listed in the manuals. Be sure to specify for S-line to get 
the correct holder and circuit capacitance. I think the holder is HC6/U.

The formula is always injection frequency is 3.155 MHz above the lower 
band edge. Above 12 MHz, the crystal is at half that frequency. You can 
use any crystal that will plug in. In my receiver, I have added a little 
switch and socket mounted on top of the front tuning rack post and 
switch from the main crystal switch to that socket so I can insert 
single crystals easier than putting them into the crystal board. And 
with an adapter or two I have used several crystal holders from FT-243 
to HC-48. Most any crystal calibration capacitance will work, just if 
its an original frequency, its harder to get the dial marker to indicate 
the correct frequency every 100 kHz.

With that formula you can make the receiver tune any range you want 
between about 3 and 32 MHz. With a couple modes I made my dad's S-1 tune 
160 meters for a while. Just a different crystal in the first position, 
4.955 would have been perfect and some added padding capacitors on the 
coils for that bandswitch position. Cost at least one 80 meter position.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

On 7/31/2012 1:47 PM, Michael Raskin wrote:
> Rather than reinvent the wheel, I'm sure someone has the answer for this.  I
> have a KWM-2A and I want to get crystals for 30, 17, and 12.  The crystals
> cover 200kc, but 12 and 17 are only 100kc, and 30 is only 50kc.  What
> crystals frequencies should I order from International Crystal?   I believe
> the holder is HC50/U.
>
> Mike W4UM
>