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

2009-12-29 Thread 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" of

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

2009-12-29 Thread David C. Partridge
they suspect there's a problem with it they won't look at the time clock. D. -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bill Hawkins Sent: 29 December 2009 17:17 To: 'Discussion of precise time and frequency measu

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

2009-12-29 Thread Peter Vince
Hi Rob, Actually they are controlled from a low bit-rate signal phase-modulated onto Radio-4 long-wave (198KHz). If you have an SSB or CW receiver that tunes down to that frequency, switch on the BFO and look at the output on something like Spectrum Lab, and the phase modulation is readily s

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

2009-12-29 Thread Bill Hawkins
I wonder how the power company changes the meter rate, based on the local timer. Are there two different meters, with a separate circuit for cheap loads? Perhaps not, because you continue to run your computers without interruption. OTOH, you said in the first posting, "Sometimes we hear the contac

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

2009-12-29 Thread Rob Kimberley
-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Dr. David Kirkby > Sent: 28 December 2009 23:22 > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Can a quartz crystal go off by 2% ? > > I'm on the so-called 'Economy 7

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

2009-12-29 Thread Dr. David Kirkby
Dr. David Kirkby Sent: 28 December 2009 23:22 To: Discussion of precise time and frequency measurement Subject: [time-nuts] Can a quartz crystal go off by 2% ? I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 07

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

2009-12-29 Thread Steve Rooke
l Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Dr. David Kirkby > Sent: 28 December 2009 23:22 > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Can a quartz crystal go off by 2% ? > > I'm on t

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

2009-12-29 Thread Rob Kimberley
Hz supply. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David Kirkby Sent: 28 December 2009 23:22 To: Discussion of precise time and frequency measurement Subject: [time-nuts] Can a quartz crystal go off by 2% ? I&#

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

2009-12-29 Thread Dave Baxter
ing. It would not even pay for itself in my lifetime! Best Regards. Dave B. PS: Does anyone else miss the odd digest mail at times? -- Message: 4 Date: Mon, 28 Dec 2009 19:47:41 -0500 From: Bob Camp Subject: Re: [time-nuts] Can a quartz crystal go off by 2% ? To:

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

2009-12-28 Thread Dr. David Kirkby
more than usual. Dave --- On Mon, 28/12/09, Dr. David Kirkby wrote: From: Dr. David Kirkby Subject: Re: [time-nuts] Can a quartz crystal go off by 2% ? To: "Discussion of precise time and frequency measurement" Date: Monday, 28 December, 2009, 23:58 ALAN MELIA wrote: It is po

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

2009-12-28 Thread Dr. David Kirkby
Bob Camp wrote: Hi Even with a tuning fork crystal, anything past about 0.2% is a very large changel. That's true for tuning and also true for normal aging. I suspect that something mechanical has happened. 1) A cracked crystal - unlikely 2).An electro magnet in the driving circuit no longe

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

2009-12-28 Thread ALAN MELIA
vid Kirkby > Subject: Re: [time-nuts] Can a quartz crystal go off by 2% ? > To: "Discussion of precise time and frequency measurement" > > Date: Monday, 28 December, 2009, 23:58 > ALAN MELIA wrote: > > It is possible the crystal has succumbed to a > mechanical

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

2009-12-28 Thread Bob Camp
Hi Even with a tuning fork crystal, anything past about 0.2% is a very large changel. That's true for tuning and also true for normal aging. I suspect that something mechanical has happened. 1) A cracked crystal - unlikely 2).An electro magnet in the driving circuit no longer firing fully.

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

2009-12-28 Thread Dr. David Kirkby
Bruce Griffiths wrote: If the trimmer in in series with the crystal and not shunted by another capacitor then the crystal will no longer control the oscillator frequency. 0.1pF or 0.01pF in series with a tuning fork crystal instead of the nominal value (20pf?) will make a singnificant differenc

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

2009-12-28 Thread Bruce Griffiths
or 0.01pF in series with a tuning fork crystal instead of the nominal value (20pf?) will make a singnificant difference. Thanks for the idea of the ferrite rod. Dave Bruce --- On Mon, 28/12/09, Dr. David Kirkby wrote: From: Dr. David Kirkby Subject: [time-nuts] Can a quartz crystal go off b

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

2009-12-28 Thread Dr. David Kirkby
uld not have thought a trimmer cap going open-circuit could have induced a 2% change. That seems an awful lot. Thanks for the idea of the ferrite rod. Dave --- On Mon, 28/12/09, Dr. David Kirkby wrote: From: Dr. David Kirkby Subject: [time-nuts] Can a quartz crystal go off by 2% ?

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

2009-12-28 Thread ALAN MELIA
runs out. Alan G3NYK --- On Mon, 28/12/09, Dr. David Kirkby wrote: > From: Dr. David Kirkby > Subject: [time-nuts] Can a quartz crystal go off by 2% ? > To: "Discussion of precise time and frequency measurement" > > Date: Monday, 28 December, 2009, 23:22 > I&#

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

2009-12-28 Thread Dr. David Kirkby
I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 0730 - i.e. a 7 hour period when electricity demand is low. I'm no longer heating by electric, but do run some computers 24/7. It's not totally clear whether this saves me money or costs me