[Collins] crystals for kwm-2 and power supply

[Dr. Gerald N. Johnson]

On Mon, 2008-07-07 at 16:07 -0400, yash at aol.com wrote:
> Looking for a crystal  to cover 17 meters. Called all the normal 
> sources,jan,international etc. they are saying a month + or so before 
> they can ship.
> I was hoping to find one sooner.
> frequency is 10577.500kHz..... coverage is 18MHz to 18.200MHz     
> Collins part # is 290-9082-00
> 
>   Would also like to find a 516-f2 power supply,with or without a case. 
> looks not important.
> 
> thanks
> dale wt4t
> ______________________________________________________________
If you need a crystal faster than a custom made, you may have to root
through barrels of surplus crystals to pick out something close. I
compute that a crystal at 10.6115 MHz puts 18.068 at 0 on the dial or
10.5615 MHz puts 17.968 at 0 on the dial and 18.168 at 200 on the dial.
So any crystal between (and including) 10.5615 MHz and 10.611 MHz will
allow 17 meter operation.

A crystal at 7051.666 KHz might work, but since it will be tripling
instead of doubling the receiver sensitivity and transmitter output may
be low. Allowing for loss of direct calibration as above, a crystal
between 7.041 and 7.0743 may work. In the old days, we might have
grabbed a surplus 7.000 MHz crystal in a FT-243 holder and ground it to
frequency with toothpaste or kitchen cleanser. Today silicon carbide
(wet or dry) supported on our old slab of plate glass is very effective.

One other possible source for odd frequency crystals is Dan's Small
Parts. I think probably those that used to be at Surplus Sales and
Burghardt have been grabbed for exactly the same reason you wish one.

Also check with Peterson Crystal at Council Bluffs IA for a custom
crystal quicker than JAN (may work someday) or ICM (will work the first
time its delivered but it won't be delivered tomorrow).
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer