[R-390] 200 kHz Crystal

[Michael Murphy]

Bob,

Ocean State lists a ceramic resonator for 200 kHz for $1.39. This may not
oscillate without exploding  but it sure would make an interesting
foundation for a plug-in solid state calibrator source for the 390A. No idea
if it would be stable over temp, but if it were kept at a constant temp, it
may work.

http://www.oselectronics.com/ose_p68.htm

Blip Blip Mike Murphy WB2UID


----- Original Message ----- 
From: "Bob Camp" <ham at cq.nu>
To: "Mark Huss" <mhuss1 at bellatlantic.net>
Cc: <R-390 at mailman.qth.net>
Sent: Monday, February 21, 2005 10:11 PM
Subject: Re: [R-390] 200 kHz Crystal


> 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
> >
>
> _____________________________________________________________
> 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