[time-nuts] Odd HP 117A configuration

Scott McGrath scmcgrath at gmail.com
Mon Sep 8 23:34:21 EDT 2008


Since everything is now UTC is it worth preserving this electric
offset system ?    It would certainly be a neater package if the TRF
module actually fit within the case!   My thoughts were to combine
this with a 105B

On Mon, Sep 8, 2008 at 4:45 PM, Tom Van Baak <tvb at leapsecond.com> wrote:
>> All,
>> I purchased a 117A at a hamfest years ago and am just now looking into
>> it.     This 117A is a bit different from the ones in the manual and
>> in pictures up on the web as it incorporates a telechron reduction
>> motor installed in fthe area in front of the TRF module harness
>> connector.     Had not looked at this unit much as I did not have a
>> manual which I now have as the power supply board (A9) had a charred
>> hole blown in it.     The TRF module does not insert fully into the
>> chassis due to the presence of the clockwork module.    Interestingly
>> enough the clockwork looks like HP installed it or someone did a VERY
>> good job.  Does anyone know what this clockwork is intended for?
> Scott,
> I have a 117A like this too. The purpose of the motor and
> its gears was to slowly move the phase in order to offset the
> received frequency by some parts in 10^10th. This was done
> in the 60's and early 70's to convert between UT (universal
> time) and AT (atomic time). All part of leap second history.
> /tvb
> http://www.LeapSecond.com
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