Hi Jon and all,
I have had acceptable results with Nichrome wire as the resistive
part of parasitic suppressors in FM broadcast transmitters using the
4CX3500A up to about 5500 watts CW. Probably hundreds of these units
are around the world with this circuit in them. Also used the wire in
the prototype of my 100 kW x 2 amplifier at 2800 KHz which I built
two years ago. However, in that unit, I finalized the prototype
around small Carborundum type resistors because they were easy to
mount, and well, they worked too. I also find a bit of ferrite is
helpful in some magic absorbers. I do not built these things from
paper models and equivalent circuits, but with a network analyzer
sweeping a cold amplifier circuit. Right now I have no suppressors in
the big amp.
OK, my 2 cents worth. If I get a chance to digitize some plots from
the ANA, I could show some examples of before and after sweeps of the
amplifier S21 response.
John
K5PRO
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