[Amps] Miller-Larson effect on thoriated tungsten filaments

[k7fm]

I think it was Bill Orr who commented that when he was working with 
Eimac, someone sent back more than one pair of 3-500 tubes under 
warranty because they were bad.  He called the fellow up and learned 
that the ham was shutting down the filament between transmissions. He 
told the fellow to stop that habit and did not get any more 3-500 tubes 
back from him.

73, Colin K7FM