[Amps] Checking a 3CX800A7

[Kelly Jones]

Hello Ampsters...
 
Well, I think my questionable tube might not be questionable any longer.
Last night while on 160, I noticed the grid current on my LK-800 jumped
from nearly nothing to around 100 mills.
 
When I bought the amp several years ago, I noticed one of the tubes
looked like it had a rough life.  It was pretty discolored and the
plating on the fins had begun to "curl".  
 
So my question is this - is there a way to check the tube with a VOM for
leaks or shorts?  The HV looks good, but where the amp used to tune for
max output, I'm now getting max grid too.  Fortunately I have a brand
new set of 3CPX800s that I bought in anticipation of this day coming.
 
73
Kelly - N0VD