[time-nuts] Sidereal timekeeping

[Jean-Louis Oneto]

Hello list,
I tried that a long time ago, but the trap I went into was that the 
capacitance of the 'scope probe was pulling the frequency down, so I ended 
with a crystal too high in frequency...
I'm not sure that you can control the frequency without significantly 
perturbing it. And waiting to check the rate between each tuning step would 
take a long time...
Regards,
Jean-Louis
----- Original Message ----- 
From: "Bruce Griffiths" <bruce.griffiths at xtra.co.nz>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Tuesday, May 17, 2011 1:22 AM
Subject: Re: [time-nuts] Sidereal timekeeping


> Jim Lux wrote:
>> On 5/16/11 2:58 PM, iovane at inwind.it wrote:
>>> Neville,
>>> at present I have not enough skill with micros to solve the problem.
>>> I think I will try modifying a crystal. This would not be that difficult 
>>> using
>>> a lapping sheet or the like. And opening the can would be quite easy 
>>> using hot
>>> air.
>>
>> or a fine jeweler's saw or tubing cutter.
>>
>> As you pointed out, the crystals are cheap, so you can afford to ruin a 
>> few while figuring out how to do it.
>>
>> (and then, remember us all, when you're a multi-billionaire having 
>> cornered the market on sidereal rate crystals<grin>)
>>
>>
> Since the 32 kHz crystal is likely to be a tuning fork form, one merely 
> needs to shorten the tines to increase the frequency.
> It may be feasible to do this without removing any of the electrode 
> metallization.
>
> Bruce
>
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