I worked on a time and date clock thingo for a PABX way back in 1979 that used a 4.096 kHz crystal in a 9 pin vacuum tube envelope the same size as a 6BM8 etc. The crystal itself was about 3mm square and 50mm long. It was gold plated on each of it's four long faces, the drive going to one opposite pair and another set of wires going to the other opposite pair. With the circuit running, you could pull the xtal from it's socket and hold it up to your ear and because of the low damping in the vacuum you could hear it ring (via mechanical conduction) at it's resonant frequency for about 15 seconds as it gradually died away.Frank Berry said:
I don't know what frequency deviation is tolerable according to the standards.
But series and parallel resonance are usually quite close to each other.
Am I giving info away for free that I'd rather kept for myself ?
Regards
Charles
No. This has been covered before........
The "series" and "parallel" resonances that are refered to when ordering a crystal only state what kind of load the crystal saw when measuring the point of the series resistance minimum.
Or resonance. They are a few kHz apart.
And then there is the anit-resonant frequency.........
Jocko
The "series" and "parallel" resonances that are refered to when ordering a crystal only state what kind of load the crystal saw when measuring the point of the series resistance minimum.
Or resonance. They are a few kHz apart.
And then there is the anit-resonant frequency.........
Jocko
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