[TenTec] Centurion

[Lyle Dunlap]

Ken

Not sure what  tubes your talking about.  Only some tubes require forced air
cooling.  However the thing I would do if I were doing it would be to
start out with lower voltage on the filament and gradually bring it up to
full fil voltage.  Leave it that way for say an hour.

I have tubes here way over 60 years old and still good.  Have an amp here I
built 3 or 4 years ago using a tube built in 1929.  An RCA Radiotron 849.

A bit of trivia you might find interesting is that the tube when it first
came out in 1929 sold for $168.00.  I use that tube today and run about 450
watts output with it.

The 849 was used as one of the modulator tubes in the Collins 20B amp that
Adm Byrd took to the South Pole on the James Rupert,  forget which year now
but was in early 30's.

Lyle W9FCX