[time-nuts] Glass Envelope Quartz Crystals

[Ian Stirling]

On 02/02/2016 03:24 PM, Don Latham wrote:
> You have it right, iovane. At the least, they should be protected from light,
> thermal radiation, and emf.   Won'drous things will happen if the crystal and
> its structure are subjected to radiation through the glass. I'd suggest a foam
> wrap in a tin can as a minimum. Put the oscillator cat in there too.

   I have a 100 kHz glass "Crystal Unit" made by G.E.C., type JCF/193
with a serial number and sealed in a valve/tube with seven pins.
I removed it from my Eddystone EA12 that I bought from Tom Roberts,
G3YTO, SK 1985. It has a black shield with a spring inside at the top
so that it grips the base. The valve that produced 100 kHz markers for
dial calibration failed and I don't use the EA12 these days.
It will be interesting to see how stable it is and what the effect
of light and heat on it is when I start experimenting.

Ian, G4ICV, AB2GR
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