[R-390] 200 kHz Crystal

[Bob Camp]

Hi

The 17 MHz crystals are still made and relatively easy to find. It's 
the 200 KHz crystals that are a problem. The radio is in big trouble 
with no 17 MHz crystal. Without a 200 KHz crystal it still limps along 
with no calibrator.

Stuffing a 100 KHz crystal into the 200KHz position might work with 
minor circuit modification. I am not sure that helps since all of the 
old crystals below 500KHz are pretty darn tough to find. There are 
people who make them but the cost is staggering.

The simplest replacement probably is a (yikes!) solid state divider 
tacked on to a cell phone TCXO. In order to switch it on and off you 
probably would have to do at least one solder junction inside the 
radio.

	Take Care!

		Bob Camp
		KB8TQ


On Feb 21, 2005, at 7:15 PM, Mark Huss wrote:

> Still looking for a 200 khz crystal for the Calibrator.  Fair Radio is 
> out
> of stock.  I hear that since the heater for the 200 kHz and 17 MHz 
> crystals
> are always on, that the life of these is limited.  Is anyone 
> interested in
> developing a frequency doubler for a standard 8.5 MHz crystal to 
> replace the
> unobtainium 17 MHz crystal?
>
> _____________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:R-390 at mailman.qth.net
> Unsubscribe: http://mailman.qth.net/mailman/options/r-390
>