[time-nuts] BTTF : Austron 1210-C Crystal Clock

Tom Van Baak tvb at LeapSecond.com
Mon Jun 12 00:45:47 EDT 2017


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" <j99harman at gmail.com>
To: "Discussion of precise time and frequency measurement" <time-nuts at 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 <paulswedb at 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




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