[time-nuts] Attempting to start HP5061A

[Matt Krick]

Hello,

I recently acquired a HP5061A and I am attempting to start it but there are
some things that are puzzling me.

Per the manual I have left the unit plugged in for 24 hours with mode set
to CS OFF set to and I have observed the Ion Pump readings go to 0 after
about 3 or 4 minutes of first plugging it in.

So now I am attempting to power up the tube by switching to Loop open and I
can hear another power supply engage. My Ion Pump reading climbs to about
30 after about 10 seconds and then the power supply shuts off. Then I get
into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump
going between 20-30 or thereabouts.

I'm not sure if this is normal and part of the pumping down process.
Should I leave it on or keep trying to run it on CS OFF?

Am I correct in assuming that with CS OFF the +3500V supply is running and
that is what is acting as the Ion Pump to evacuate the tube, and then when
I switch to Loop open that also powers  up the Cesium Heater and the -2500V
supply?

I have experience with high power Triodes and Tetrodes where you run the
filaments without high voltage to help evacuate the tube so I'm unsure how
a tube like this operates.

Thank you!