[MRCA] Re: BC-659

[W7QHO at aol.com]

In a message dated 10/12/04 11:13:27 AM, mrhistry at cox.net writes:


> Discovered two crystal slots in the FM radio (commonly known as the Jeep
> radio). Does anyone know what xtals this set needs?
> Roger
> k0rmk
> 

Roger,

These are 2 channel FM sets operating in a range of 27 - 38.9 MHz.   Range 
covered in 100 kHz   increments, 120 channels.   The required xtal frequency is 
given by the formula:

   xtal = (channel freq. - 4.3)/4

ex. for a channel frequency of 29.6 MHz the crystal freq. would be 
(29.6-4.3)/4 = 6325 kHz

There was a 120 xtal set for these rigs, the lowest unit ground for 5675 kHz 
(channel 270, 27 MHz) up to 8650 kHz (channel 380, 38 MHz).   Channel 286 
would be 28.6 MHz, etc...

Deviation on these sets is about +/- 40 kHz so legal today only above 29 MHz. 
  The manual cites a working range of 3 miles but I have achieved up to 25 
miles over a clear, salt water path with a pair of these.

For a complete rundown see ER #135, July/Aug 2000. Article also describes a 
work around for a special battery required by these sets which is, of course, 
unobtainable today.

Dennis D. W7QHO
Glendale, CA