[TenTec] 422 Centurion blowing fuses...

[Ken Brown]

If you need a new transformer think of it as an opportunity for an 
improvement to the amplifier. The improvements could be higher plate 
voltage, and perhaps using a separate transformer for the filament 
voltage. By using a separate transformer for the filaments, with 
multiple primary taps, you can adjust for optimum filament voltage. That 
will give you  enough emission and maximum tube life. Directly heated 
cathode tube life is inversely proportionate to an exponential function 
of filament voltage. A small reduction in filament voltage, while still 
maintaining enough emission from the cathode, can greatly increase your 
tube life.

If all the transformers have to fit inside the cabinet with the RF deck 
and the HV transformer this may be difficult to the point of not being 
practical. If there is a separate power supply from the RF deck, it is 
much easier to do.

DE N6KB