AFAIK, the Cesium unit in the PRS-50 is a 5045A module. You mentioned a
'4201A module' so this info might not apply.
A couple of years ago, I helped a guy on eevblog fix a Datum 4040A which
used the same 5045A module as my 4065A Cesium. It turned out that most
of the capacitors in his 5045A
Dirk
Kind of a good and bad thing. Shame it doesn't work, oh boy now you get to
dig in. Nothing to lose so the fun begins.
I am of the belief ionizers are low ohms. Maybe not that low but low. If
its actually shorted somehow to the case then as Bob suggests you might
float it with an independent
Hi
Just as a guess, it would be rare for a “heated wire” type of thing to have
much over a
10:1 ratio between hot and cold. Most have ratios that are less. (think of a
light bulb …)
If you suspect the ionizer, I’d suggest working out just what it’s resistance
is. If it’s down
below 0.1 ohms
Hi,
I acquired a PRS-50 Caesium beam frequency standard in more-or-less working
order back in 2011. The manufacture date was February 2001, so the tube was
probably exhausted by this stage, but it did still achieve lock so may have
been in storage for some time rather than run for the whole of
