Hi Jean-Louis, I'm pleased to hear that you had success trying to modify such a crystal, though you had problems checking the frequency. Regarding this aspect that I'm aware of, my idea is to "hear" to the 32kHz signal with a HP3586A selective voltmeter or a R&S VLF receiver. Further, as electric-guitar players do know, the 1 pps pulse of wristwatches is easily picked up by guitar pickups (many use wristwatches to check pick-ups). These pulses could be compared to pulses coming from, say, a properly set 3325A. And I will use a wall-clock machine which I suppose is stronger than a wristwatch. As there is no issue, to some extent, with the lenght of wires between the crystal and the circuit at these frequencies, I was also speculating about a quasi-continuous monitoring of the trimming process, where for trimming I could use a disc of lapping sheet glued to a Dremel disc.
Well, just arrived another suggestion from Bob LaJeunesse too. Regarding software applets (your other post) I have several of them, but as I said my problem is different. Thanks, Antonio I8IOV >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.griffi...@xtra.co.nz> >To: "Discussion of precise time and frequency measurement" ><time-nuts@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, iov...@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 >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > >_______________________________________________ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.