[Amps] Testing amp with no air flow

[Harold Mandel]

Dear Rick,

When tweaking my dual 3CPX1500A7 amp under the RF deck what I did was
to fabricate a piece of 1/8" thick Plexiglas clear plastic in the same
fashion as
the lower plenum cover with the addition of tiny holes I drilled for the
insertion
of screwdrivers and meter probes, leaving them taped over wit painter's tape
until I needed to accesas the holes.

That way I could pressurize the plenum to my heart's content without fear of
trashing my $2800 tube set.

Hal 
W4HBM

[snip]
I will soom be ready to apply power for the first time to a homebrew 8877 
amp.  I need to make adjustments under the chassis with the tube filament 
lit and was wondering how long I can run the 8877 with just filament voltage
applied and no air flow?   I don't see the subject addressed in the Eimac 
spec sheet.
[snip]