[Amps] HV Turn On Delay

[Steve Thompson]

Mike wrote:

> Question: Do you have to wait three minutes from the time the 
> filament voltage is turned on until the HV is applied?
As I understand it, the danger is drawing current before the cathode is 
fully heated up - if you do, all the current flows out of the spots that 
are hottest, and this can mean the current density is too high for the 
cathode material and it ends up damaged. As long as the valve can't draw 
current during warmup it should be safe.

Steve