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Old August 27th 04, 10:54 AM
legg
 
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On 26 Aug 2004 22:40:36 -0700, (Bill N2CQR
MOHBR) wrote:

I'm trying to improve my limited understanding of how RF amps operate.
I've been studying "Solid State Design for the Radio Amateur" and
Experimental Methods in RF Design"


Keep studying.

The static bias is the zero-signal drain current and your calculation
is for static DC loss. Signals applied to the gate can add to the
drain current, as well as subtract.

RF final amps are unlikely to be biased classA. Class B and C will
have the final acting more like a switch. Current is imited by the
load impedance - which in this case is a complex impedance that looks
like 50 ohms at the output only.

As to the answer for your posting - the fet in this case is biased by
varying gate static voltage using the variable resistor in the
schematic, as instructed.

RL