[Amps] Testing amp with no air flow

[Jim Nowotarski]

For what it's worth, when I brought up my homebrew 4CX800A amp, I
bought  4 temperature crayons (Tempilstiks) from McMaster-Carr and
marked the tube on the ceramic and metal at the seals. I don't
remember the temps I chose, except that one was as close as I could
get to the "do not exceed" temperature without going over. I think I
went 50, 100 and 150 C below the max temp.
As it turned out I only melted the lowest one on a full power check,
and none with just the heater on.
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Jim Nowotarski