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Old September 9th 05, 09:16 PM
Steve Nosko
 
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I shouldn't, but will. You don't say, but I think you are puzzled by a
decreasing load impedance causing a decrease in collector current. I'd have
to think about it, but I'd first Try modeling that LC filter at resonance to
see if it gives an inverse function like the 1/4 wave line.
A "gut" reaction tells me that a decreasing collector current for *either*
an increased or decreased load Z would not be a surprise...

Steve K9DCI


"Cecil Moore" wrote in message
...
Tim Wescott wrote:

Cecil Moore wrote:
The amp is a Class E/F design from Jan/Feb 2004 QEX. Why would
the drain current fall when the load is decreased from 100 ohms
to 25 ohms?


The output filter of an amplifier can act like a 1/4 wave (or 3/4 wave)
transmission line, ...


I should have described the output circuitry. It's a push-pull
LC tank circuit with DC supplied by the coil center-tap. The
output is just a link coupler. The low-pass filter is a single
series L and single C to ground.
--
73, Cecil, http://www.qsl.net/w5dxp


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