Pinning the Plate Current meter... not good, probably you need to reduce
Tube specs, Plate Current, show 175ma per tube, or 700ma for 4 tubes.
Sometimes on initial tuneup when you peak output, grid current may soar...
if so, then (quickly) increase loading to bring grid current down, (and to
be nicer to your ouput network) to spec levels. In all cases while tuning,
or at final touch tuning, it is better to have a little more loading than a
little less loading.
Might be a good idea to preset before tuning, the load control to 3/4 of
full Clockwise Rotation. Then back off, if necessary.
Some people will tune for max output, carefully paying attention to grid
current, and then nudge up the loading a little, until you see a small
percentage DROP in output. That will tend to keep your grid current down,
and be less stressful to the output tank.
Here are some sites with info:
>From: Jan Ditzian <email@example.com>
>Subject: [Amps] AL-811H maximum Ip
>Date: Wed, 22 Aug 2007 11:54:02 -0400
>I have an AL-811H, and I would like to know the maximum plate power, Ip,
>when tuning this radio. I am not using a pulser. The instructions
>mention a limit for the grid current, and then tell me to peak the
>output. However, I find that if I do this, I pin the Ip meter while not
>quite reaching the grid current limit.
All the Best, 73,
Pat Barthelow firstname.lastname@example.org
Jamesburg Earth Station Moon Bounce Team
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