Tom Mandera wrote:
> I switch to OPR and key the exciter. I'm supposed to see 50-80ma of
> plate, but I see 100ma immediately.
This refers to the plate current with ZERO drive, the STBY/OPR switch in the
OPR position
and the RELAY connector on the back shorted to ground. You can check this
without an
exciter connected.
> I heard the (tube?) sizzle (sounds like a good weld, not a good thing in
> a radio) while attempting to increase the exciter drive to hit 125ma of
> grid, and never reached it.
Probably an arc in the tank circuit or (hopefully not) the bandswitch, caused
by
underloading. Do NOT allow this to continue, it will do real damage!
Make sure that you adjust the load control high enough. When my SB-1000 is
tuned to full
output I have about 120 ma grid current. With less drive you should see less
grid current.
Too much is an indication of underloading.
The simplest way to learn to tune up an amplifier is to get an experienced ham
to show
you. It's easier than it sounds in the SB-1000 manual, which is very confusing.
Just
remember to keep the grid current down (and the plate current to 400 ma).
Incidentally, the RF output meter is very inaccurate and is useful only for
relative
indications (at least, that's how mine is).
--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
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