[Amps] AL-80A tube glow

[Kim Östman]

Howdy,

I've been using the AL-80A successfully (apart from some rare arcing  
inside) for about 10 years off and on, including contests.

Something that I've paid notice to only as of late in the 3-500Z tube  
is a gradually increasing orange or light red colored glow in the  
metallic cooler wings(?) as one sends CW of SSB during an "over". Is  
it normal for the tube to begin glowing like that, or is something  
wrong?

The SWRs on my antennas are below 2:1, tube plate current around  
450-500 mA (which I guess is stretching it a bit), and grid current  
around 200 mA. Output according to a Daiwa meter is between 700 to  
1000 watts depending on the band.

Thanks in advance!

73 / Kim OH6KZP