[time-nuts] Can a quartz crystal go off by 2% ?

[Philip Pemberton]

Rob Kimberley wrote:
> AFIK a lot of the clocks were radio controlled from MSF Rugby (now Anthorn,
> Cumbria). You would need to have some sort of automated system to
> accommodate daylight savings switchovers in Spring and Autumn. That said, I
> would have thought once synchronised, they would "tick" off the 50 Hz
> supply.

Radio 4, actually.

There's a low-speed phase-modulated signal riding on the 198kHz carrier, 
which encodes the clock time and a few bits of data for "radio 
teleswitching", i.e. Economy 7.

If you meddle about a bit with a PLL, you can even use it as a frequency 
reference (it's apparently driven off a rubidium oscillator and the NPL 
monitor its frequency in relation to the UK "standard" frequency, same 
as they do with GPS and the Rugby/Anthorn/MSF time signal).

The fact that the meter isn't resetting itself implies that there's more 
wrong with it than just the crystal. I'd go with a failure in the RF 
section that's caused it to lose the teleswitching signal and 
date/time... There's no RF (as far as it's concerned), thus it's fallen 
back to the quartz in the dim hope that maybe, just maybe, it'll start 
hearing the distant voice of R4 in the not too distant future...

It's another possibility, anyway.

-- 
Phil.
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