[time-nuts] Odd HP 117A configuration

[Tom Van Baak]

> 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