[Amps] 4CX250B in grounded grid and screen configuration

[Angel Vilaseca]

Hi,
I have several used 4CX250Bs that I want to try to put to use.

State of the tubes is unknown. They are pullouts. I will test them 
including hipot, as was detailed on this list a few days ago.

Now if some pass the hipot and other tests, there is still the secondary 
emission problem with an used valve of this kind.

So I was wondering if would be possible to use a 4CX 250B with both its 
grid and screen connected together to ground.

Will it behave as a grounded-grid triode?

Will then secondary emission still be a problem?

How many 4CX 250Bs connected in parallel woul it take to have a cathode 
circuit with a reasonable match to a 50 Ohm input drive?

Vy 73

Angel Vilaseca HB9SLV