[TenTec] Titan II Bias issue

[kr7o at vhfdx.com]

I am repairing an amp that was from a friend's estate and have fixed 
several issues, but now when I switch the amp to Operate, considerable heat 
is coming out of the exhaust, so it appears the tube is partially biased on 
all the time.  I have loaded the amp many times up to about 1kw output, so 
I am reasonably confident that the tube is OK.

According to the manual, the cutoff voltage is supposed to be -130v, but 
with 70vac on the primary into a half wave bridge, I cannot understand 
where they are getting -130v from.  My bias voltage is only -80v in RX.  I 
get up to -95v with the bridge unloaded, which is close to what would be 
expected from a half wave bridge.  The screen voltage supply appears to be 
functioning normally.

I will admit, I am not much of a tech, but I DO know how to work around 
high voltage and avoid exposed plate voltage unless absolutely 
necessary.  I have gotten this far, and would love to get this amp running 
if anyone has experience with this amp and does not mind helping me sort 
this out.  I have more history and measurements, but I will spare the list.

Thanks,


73, Robert KR7O/YB2ARO, DM07ba/OI52ee  (ex.  N7STU)
DXCC  6M #1122
WAZ  6M #112
VUCC  6M, 2M

www.vhfdx.com (KR7O/YB2ARO pages)
Looking for old VHF QSL cards and logbooks.