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" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> 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 <[email protected]> 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 -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
