[time-nuts] How to get unknown frequency quartz crystalsoscillating

David J Taylor david-taylor at blueyonder.co.uk
Sun Jun 5 10:22:45 EDT 2016


The original question related to crystals that ran down into the 10’s of KHz 
range. For those, a
high resistance is not unreasonable at all. For more “normal” AT cut 
resonators in “big" packages
it is not unreasonable to expect the resistance on the fundamental to be 
approximately the same
as the frequency in MHz. As the overtone goes up, it is not unusual for the 
resistance to go up
as the overtone number. There are an almost infinite number of qualifiers on 
all of that.

The range of crystal resistance between things like 3 MHz AT’s and 32 KHz 
watch crystals is one
of the things that makes building an one size fits all oscillator difficult.



There was a discussion about measuring 32 kHz crystals in the VNWA Yahoo 
group recently, and Tom posted a note describing how to do it and get 
sensible results:



It struck me that a noise generator and the spectrum display for the Airspy 
might be another low-cost way at least for HF crystals:


David GM8ARV
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor at blueyonder.co.uk
Twitter: @gm8arv 

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