[Boatanchors] Pair of Crystals needed

[Al Klase]

Rob,

Yes, I should have included those as well. The crystals with the 
three-digit channel numbers, 270-389, produce output frequencies of 27.0 
to 38.9 MHz. The multiplier in this case is 72. So channel 328 = 32.8 
MHz /72 = 455.555 KHz etc.

Looks like anything close was already picked from your E-bay box. They 
were popular for homebrew crystal lattice filters in the old days.

The 21st Century solution is programmable crystal oscillators. The 
distributor does this to your specification. Prices appear to be way 
less that 10 bucks each. Start with Digikey.

Al

On 3/8/2014 10:00 PM, Rob Atkinson wrote:
> you mean something like this:
>
> http://www.ebay.com/itm/256-VTG-CRYSTAL-WESTERN-ELECTRIC-FT-241-SIGNAL-CORPS-HAM-RADIO-/331040709936
>
> Rob
> K5UJ
>
> On Sat, Mar 8, 2014 at 7:46 PM, Al Klase <ark at ar88.net> wrote:
>> Hello Keith,
>>
>> Probably your best shot is the FT-241 tank radio crystals, the armor
>> frequencies in particular. They are labeled channel 0 thru 79. The operating
>> frequency is 20 MHz + (ch. # divided by 10). So Channel 45 is 24.5 MHz, and
>> the crystal frequency is F / 54 or 453.7 KHz , Channel 48 would get you
>> 459.3 KHz for a spread of 5.6 KHz. Other combinations my be acceptable.
>> There are entire sets of these crystals are still laying around in junk
>> boxes everywhere. We built enough to invade Japan in 1946.
>>
>> Good luck,
>> Al
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-- 
Al Klase – N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/