[Elecraft] K3: past chirp report

Bill Johnson k9yeq at live.com
Sat Jan 21 14:09:21 EST 2017


Ron, I used a wet stone that was flat and with spit.  Lots of work to get to the desired frequency.  We had a bunch of surplus Army surplus frequency oscillators that provided us with XTALs most were out of band so it was a chore, but cheap, to move the frequency.
73,
Bill
K9YEQ

-----Original Message-----


A crystal oscillator might "drift" a few tens of Hz at H.F. on its fundamental frequency but in all the dozens of xtal controlled transmitters I've built and used over the years, nothing greater than that. 

There were some circuits designed to "pull" the frequency of a crystal slightly - maybe a few kHz - but they did tend to be unstable. Pulled too far, the crystal oscillator would stop being controlled by the crystal at all and simply become a free-running oscillator. 

Many novices used "surplus" crystals from military gear and it was common to find several stations on the same frequency when the band was open. So we tinkered with ways to move the crystal frequency slightly by rubbing solder or pencil 'lead' (graphite) on it but one could only go so far or the crystal would stop oscillating. 

73, Ron AC7AC



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