[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?:


The audible (1 kc) whine was probably from the model 113 or 115. See if any of the following pages remind you:



----- 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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