Gentlemen, Original poster is trying to "RESTORE" this entire old General Radio Standard ( a rack of equipment) to it's "original" glory. He simply needs a part, a unique thermoswitch or a way to fix it, not retrofit an atomic engine! This is a museum class instrument, 100kc.
May I suggest start a new thread on the better/best merits/design of temperature control. Makes it rather difficult to follow a thread as the subject has changed. Respectfully Phil ----- Original Message ----- From: "Mike Monett" <[EMAIL PROTECTED]> To: <time-nuts@febo.com> Sent: Friday, August 22, 2008 9:20 AM Subject: Re: [time-nuts] Restoring GR 1120-AB Frequency Standard > > Bruce Griffiths <[EMAIL PROTECTED]> wrote: > > > Max > > > A capacitance bridge using a transformer would be a lot more > > stable than merely using the capacitance to vary the frequency of > > an LC oscillator. > > > The advantage of a capacitive sensing technique over a light beam > > is that it has much simpler and potentially more stable mechanical > > system than when a the mercury colum interrupts a light beam. > > > Unless of course on has the Mercury column move a moire grating or > > similar setup such as making the top of the mercury column a > > reflector in an interferometer system. > > > Bruce > > Very clever! According to this web page, interferometry could give a > resolution of 0.15 nm, or close to the radius of a silver atom: > > http://www.aerotech.com/products/engref/intexe.html > > This video shows the basic principle in case you want to make your > own: > > > http://www.metacafe.com/watch/1381543/laser_interferometer_homemade_for_20/ > > You can see from the movement of the fringes how sensitive > interferometry can be. This should give unprecedented temperature > control, so maybe someone has already done it. A google search gives > lots of hits, but it is difficult to distinguish between controlling > the termperature of something, and the need for accurate control of > temperature to get stable fringes! > > Great idea! > > Regards, > > Mike Monett > > _______________________________________________ > 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.