[Amps] AL80B low power

[Gudguyham at aol.com]

What is a swamping resistor in the filament?
 
 
In a message dated 3/14/2013 10:17:25 P.M. Eastern Daylight Time,  
W3TZ at cox.net writes:

I was  testing a used 3-500z and blew the swamping resistor in the filament