[time-nuts] Ball Model PRFS 102

Mike Bafaro m.bafaro at comcast.net
Tue Sep 19 17:41:29 EDT 2017



I have a Ball/Efratom Model PRFS 102 that has lost lock as of late.  I got
the  unit used a few years ago and it would acquire lock in about 3 minutes
but now it will not lock at all.


The heater is drawing current, at first turn on it takes about 1.4A and in
about ½ hour it draws about 100ma.  So the heater appears to be working but
no lock.


The internal oscillator is P/N 100318-003 and I opened it and it has 4 pc
boards connected with a flex board and they are built around the physics
module that in a deep draw case so that I cannot see the lamp.  If I take
the bottom cover off of the module I can see the physics case and I think it
has a hole in one side – is that to view the lamp?  


I am told that the lamp fails because the RB is coating the inside of the
glass and it can be revived by heating the lamp with a  heat gun.  Is that
true?  In this model is it easy to get to the lamp or is it more like brain


There is a similar module on Ebay P/N100318-001  but it has a board on the
side instead of the subD connector and the board on the side may hit the
power input block on the back panel.  I could buy it at $149.


I am an electrical engineer that worked at Motorola for 37 years and have
used one of these at Moto a few years ago.


I have enough test equipment to do the job
  can you give me some help to
get it running again.




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