During the recent Volta RTTY contest, my Alpha 78 popped the 15 amp line
fuses while running about 1200 watts in "band pass" mode on 40 meters.
I replaced them and kept an eye on the meters as I slowly brought up the
drive again. I saw no indication of anything wrong on the panel meters but
it blew them again right away even before reaching 1000 watts.
So I tried 20 meters band pass - no problems.
Then I went back and tried 40 meters in manual tune mode - no problems.
SWR on 40 is well below 1.5:1 - and I didn't notice any indication of arcing
- but maybe...
So, it would seem that I have something going on in the band pass circuit
but what? I haven't taken it apart yet to have a look but I'm not really
sure what to look for - other than maybe loose solder connections and such.
I thought it would be a good idea to see if there may be some past history
of issues in that area of the 78.
Any thoughts would be greatly appreciated!
Thanks,
Paul / NO9C
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