My ancient 4-400 GG homebrew amp is nearly ready for HV tests after extensive
modification and checkout. Am running the filaments tonight for the first
extended test with the blower in place. Both 4-400s are from RCA and the ages
are unknown. One has a bluish/green glow when viewed from the top of the tube.
The last time I saw such a color was on my old 866 rectifiers. I checked the
filament voltage on one tube (each has its own transformer) and measured 5.0 V.
for 120 VAC in.
Fatal flaw?
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|