rich asks:
>How much grid current do you have to run to see an improvement in IMD,
>Peter?
It peaks about 25mA, as I remember it. As the amp was built for AB1, and
changed after I put a spec an on it and had a fit, I don't have a grid
current meter. It has negative feedback with 8.2 ohm carbon resistors in
the filament returns, with suitable RF chokes across them so that the
bias doesn't change because of the grid current. IPs are about -35dB PEP
at 1Kw, with about 3400 on the plate - i can only measure to 2500 volts,
so the plate volts has to be inferred from what's halfway down the
equalising resistor chain.
73
Peter G3RZP
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