Tested everything that I could test with no 'abnormal' indications. Got
desperate. Took the finals out. Shook them to hear anything strange. Tube
elements in on noisy. Replaced both finals with new Eimacs. 0.82 resistor
hasn't blown yet.
Can't seem to get more than about 160 ma of resting plate current. All the
bias diodes check OK. (And, here's something rather strange. Shorting out
bias diodes doesn't change the resting plate current). Don't seem to able to
get quite as much output as with the old tubes and the plate tuning & load
tuning have changed somewhat. Tuning on 80M is fairly broad compared to old
tubes. The input SWR also appears to have changed. The FT-1000D is having a
harder time to match the input. Hate to think that I will have to modify the
input circuits.
But, first things first. So, I'll be trying straighten out the bias
situation first.
Devil for punishment.
Walter - VE3EN
--
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
|