{Collins} More 30S-1 tube questions

Okay, I changed out the tube to another old tube from another 30S-1 amp and
the grid current issue is gone.  Now with the other tube I get excessive
negative screen current. With aprox 15 watts drive I have negative 25 ma
screen current and about 200 watts output.  I gave it a little more drive
and heard a pop.  Now I have a negative 25ma screen current with only 5
watts drive and about 20 watts out.  I apparently effected the tube
somehow.  So now I have a leaky grid current tube sitting on the shelf, a
excessive screen current tube in the amp, and a new 4CX1500b in the third
amp.  I am reluctant to stick the new 1500b in this amp if the amp still
has problems.  I am not keen on the idea of forking out the money for a
couple new tubes, but it is what it is.  Any suggestions before I stick the
one known good tube in?

Thanks Greg WQ0P

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