[Elecraft] K3: past chirp report

[Mark E. Musick]

Ron,
Don't forget about grinding the crystal down a little using Comet or Ajax on a piece of glass.
I had crystals I moved using both methods, pencil and grinding. One to move down in frequency the other to move up in frequency.

Mark, WB9CIF

-----Original Message-----
From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Ron D'Eau Claire
Sent: Saturday, January 21, 2017 4:30 PM
To: ww3s at zoominternet.net; elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3: past chirp report

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

-----Original Message-----
From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of ww3s at zoominternet.net
Sent: Saturday, January 21, 2017 3:13 AM
To: Ron D'Eau Claire; 'Richard Fjeld'; elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3: past chirp report

Xtal controlled could still drift, especially if the rig wasn't warmed up yet….. I got my novice in 1972 and I think that was the first year we could use vfos…..


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