The most critical point in the entire amp is the temperature of the
tube seals, i.e. where the glass and metal or ceramic and metal meet.
The max temp varies from tube to tube and will be specified in the
tube's data sheet.
The only practical way to measure this is with color-changing paint.
This paint is available in a wide range of values and changes color
when its particular temp is reached. If it does not change color after
an extended period of operation, you are OK.
It's been a while since I bought any but as I recall it is available
from Mouser, Digi-Key and probably others.
The other important temperature is that of the power transformer.
After a long period of operation simply smell it. If it gives off a
hot varnish smell, it needs more cooling. That smell indicated the
varnish is overheating and is breaking down. A fan or two should fix
it, or simply back off the power.
73, Bill W6WRT
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
|