[time-nuts] Is a crystal likely to change frequency by 3% ?

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Sat Sep 13 08:12:49 EDT 2014

On 13 Sep 2014 04:39, "David McGaw" <n1hac at dartmouth.edu> wrote:
> The battery probably was going weak and the oscillator coming out of full
control by the crystal.  The tuning-fork crystal used in RTCs is not as
high-Q as a MHz crystal.  I have noticed clocks using these can go quite
slow at low voltage.  The crystal acts more like an inductor in this case
and resonates with the increased junction capacitance at low voltage.
> David

Two very different explanations from two different people about why clocks
slow when the battery gets old.

BTW Dave, please reply by my private email about whether you want the loads
measured before I send them,  given the VNA is at Keysight for


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