There's a 100C on eBay now, cheap, but it doesn't have a clock. Jeremy
On Sun, Jun 11, 2017 at 9:51 PM Tom Van Baak <t...@leapsecond.com> wrote: > Hi Jim, > > Maybe a version of this?: > > http://leapsecond.com/history/Benchmark.htm > > The audible (1 kc) whine was probably from the model 113 or 115. See if > any of the following pages remind you: > > http://leapsecond.com/hpclocks/ > http://www.radiomuseum.org/r/hewlett_pa_frequency_divider_and_cl.html > http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1959-11.pdf > http://hpmemoryproject.org/wb_pages/wall_b_page_01.htm > http://hpmemoryproject.org/news/2012/vintage_01.htm > > /tvb > > ----- Original Message ----- > From: "Jim Harman" <j99har...@gmail.com> > To: "Discussion of precise time and frequency measurement" < > time-nuts@febo.com> > Sent: Sunday, June 11, 2017 7:43 PM > Subject: Re: [time-nuts] BTTF : Austron 1210-C Crystal Clock > > > > On Sun, Jun 11, 2017 at 9:01 PM, paul swed <paulsw...@gmail.com> wrote: > > > >> But perhaps whats magical gold is the Patek Phillipe clock movement. > Just a > >> guess.I hear they are quite annoying clunkers actually. I have never > owned > >> one but a fellow in Europe was telling me you can really here them tick. > >> > > > > In my first job back in 1973 I inherited a lab that included what must > have > > been an HP 100C frequency reference. It took up most of a rack and > divided > > down a 100KHz oscillator with cascaded injection-locked 10:1 > multivibrators > > that used metal octal-base tubes. The final frequency of 100 Hz drove a > > beautiful clock that made a very audible whine when it was working. This > > must have been an option because I don't see any reference to it in the > > 100C manual. > > > > At the bottom of the rack was a Hammarlund radio to tune in WWV for > > calibration. > > > > IIRC the clock motor also drove an adjustable cam and microswitch. The > > receiver's audio was fed through the switch. I think the idea was that > you > > could accurately measure the oscillator drift by adjusting the phase of > the > > cam until you could hear WWV's tick during the short time the switch was > > closed. > > > > > > -- > > > > --Jim Harman > > > _______________________________________________ > 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. > -- Sent from Gmail Mobile _______________________________________________ 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.