[ARC5] Smart People: Triode Connecting Pentodes

[David Stinson]

Home for lunch with my beautiful bride and 
a hot cup of Joe...ahhhh...

Working on a project where I must triode-connect 
a 7984 pentode.  I have some well-used ones here 
which tested "good" that I'm trying in these "destruction" tests.
I've been told that the screen should be directly connected to the
plate through a parasitic suppressor (100 ohms) and that the
screen area is effectively added to the plate.
These are running at 500 volts on the plate at about 100 mils,
which is well within the tube *plate* ratings.
However, the screen is max rated at 250 volts 12 mA, 
or 3W max input.  My source says this isn't an issue 
when the screen is connected to the plate, but I'm not so sure.
The 7984s work OK for the first few minutes, then start folding on me.
I'm betting the screens are going.   
Who are the experts in this, and what are your points of view?

Back to work!
73 Dave AB5S