I'm aware of that.? Have done it as well.
Also it depends on bias setting and the winding of the transformer.
By that I mean how tight and careful both windings are done.
I look at it as interesting but, what use is it beyond diagnostic
if ian amp is not developing full power as then the transformer can
be ruled out or not.
I have done the reverse on a board without finals loaded and the
Drain to Source path with R/C to simulate active devices to test
if the transformation of the transformer is valid.? I use that more
at VHF and up amp designs.? Same for input transformer or
matching save for the simulated load will match the gate to source.
As to input impedance, its nice to know but it was never meant to
be 50 ohms.? Again it can check the transformer.? FYI the QSX design
the driver was power limited but not voltage swing limited so higher
input impedance was needed.? That was the design source (QSX).
The test fixture I use verifies the assembly is flat and has known?
(measured loss) as that is a full two port test then the DUT(amp or other)
is added.? Since it build it up and measure the rare case is I find a
bad attenuator or cable early in the process.
--
Allison
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