K1TTT Technical Reference


Wayne (N7NG) suggested the following procedure and by gum she now works
fine. He has a 78 and had done this once when a guest op goofed. If you own
one of these amps, put this in your files.  Thanks again, a gazillion to all.

>The solution was quick and easy (for me), though it might depend on how much
>damage has been done.  The capacitor damage was visible with the cover
>removed from the amp (POWER DISCONNECTED).  The capacitor rotor was about
>25% meshed, and the arc was in this area.  The metal was pretty well
>damaged, and it continued to arc even with a good antenna.  What I did was
>to rotate the capacitor rotor until the other (non-damaged) side of the cap
>(rotor) was meshed with the stator.  I used a visual estimate of where it
>should be, and it worked fine.  Now the damaged part of the rotor is in free
>space!  The damaged part of the stator doesn't seem to cause a problem.
>(Maybe it was only the combination of both damaged areas.)
>
>As far as I know the 374 is very similar to my 78, so it should be possible
>to fix your amp in the same manner.  The proper fix would be to replace the
>cap, but it worked so well that I haven't bothered.  I guess I should order
>a replacement cap for the next time...

What I did to get an easier guesstimate of where to readjust the rotor was:
--make a visual check of where the rotor and stator are currently positioned
(overlap)

--mark the metal on both sides of the screwdriver slot of the cap rotor with
a pen

--adjust the rotor until the screwdriver slot is perpendicular to the marks
you made (90   degrees)

--make a second visual check, should be same amount of overlap except now at
other side   of stator

Thank you Wayne!