[AMPS] SB-1000 RF choke -- results (?)

[Vic Rosenthal]

In case anyone is interested in the saga of my SB-1000, I did the following today:

1) Replaced the plate choke with the Ameritron AL-80B choke.  Whoever suggested that
resonances must be checked with the choke installed was correct; with the choke in
its place and wired up, the primary series resonance appeared at a reasonable 16 mHz;
no other noticeable resonances were found.

2) While I was at it, replaced the #14 tinned leads from the 10/15/20 meter taps of
the coil to the bandswitch with 1/4" copper strap.

Results: nada.  I still am getting only about 500 watts out on 15 meters (previously
I said 600; that was an error).   I've got plenty of drive capability; but the amp is
loaded to 400 ma plate current with about 160 ma grid current, and increasing the
drive does not produce more output.  The plate voltage is about 2850.  About 850
watts is easily obtainable on 40, and about 730 on 20.

Someone suggested that the 3-500z might be marginal, and that this would  show up
first on the higher bands.  Any comments?

Vic K2VCO

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