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

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Thu Sep 11 18:33:04 EDT 2014

On 26 Nov 2012 14:12, "David Kirkby" <david.kirkby at onetel.net> wrote:
> I've got an HP 8720D VNA. This has been out of support from Agilent
> for 8 years, so its getting on a bit. There's a clock in the
> instrument which keeps the date and time. This is losing about 1 day
> per month (rough guess), so it has slowed by a bit over 3%.
> I'm guessing this is likely to be a battery running flat, but are
> there any other likely causes? I know crystal can jump in frequency,
> but I'm guessing not by 3%, but perhaps if there was stress in the
> crystal, it might be.

I just noticed this old post of mine. Whatever did cause it to slow about
3% no longer does. It now keeps good time - although definitely not
time-nut standard.  It probably keeps within a couple of seconds per
month,  which is good enough.

Dr David Kirkby
Managing Director
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3
6DT, United Kingdom
Registered in England and Wales as company number 08914892
Tel 07910 441670 / +44 7910 441670 (0900-2100 GMT)

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