[time-nuts] Are there any company selling refurbished/reconditioned Cesium tubes?

[cdelect at juno.com]

When evaluating an instrument with a used tube the beam current is not
the best indicator to look at!
For an HP instrument If the tube label has the EM voltage listed then
with the beam current set to it's proper level check the current EM
voltage.
As the tube ages you will require more and more EM voltage to bring the
gain back to nominal.
Also performing a SN test on the tube or even a quick look at the
peak/valley/background levels
is helpful.

Cheers,

Corby