I'm confused. I've installed a Negative Bias supply in the amp and am
supplying about -100vdc to the 811A grids. The plate current as indicated
on the meter is still 100ma. If I remove the negative bias from the
grids(ground it out) the plate current increases to about 120ma. The
manual says the "Resting Plate Current" is supposed to be 100ma. In the
troubleshooting section of the manual one cause of improper resting plate
current was noted as not grounding the bias terminal on the rear apron,
effectively removing the negative bias. I did this and the plate current
went up to 120 ma from 100ma. My question is: Is the HV inducing the
resting plate current and can not be removed by apply a negative bias to
the grid? I'm learning the hard way, trial and error.
73,
Bill KO4NR
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