> In a transistorized HF RF amp is there any rule of thumb
> how to set the bias correctly, in this case for linear op.,
> forexample the standing current might be so and so many
> percent of the Ic?
> I don´t have the curves for the transistors in question so
> can´t determine it that way.
>
> 73, Jim SM2EKM
>
> It can vary a lot, depending on the transistors and the load
> conditions, but a reasonable guess is 5-10% of the peak
> current.
All of which is becomes meaningless with high power bipolar
transistors if the amplifier stage does not use an active bias
system that provides a constant voltage regardless of base current
changes with drive.
Some of the modern solid state mobile amps actually have the
transistors to negative bias voltage when drive is applied.
73, Tom W8JI
w8ji@contesting.com
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