[Amps] SB-200 input.

Bill Turner dezrat at outlook.com
Sat Jul 26 10:52:17 EDT 2014

One way to add a tuned input with little fuss is to place a "tee" 
connector at the input of the SS amp and connect a parallel resonant LC 
circuit at the tee. Make the LC circuit have a Q of between 3 to 5 at 50 
ohms and you're in business. Use a variable cap such as an Arco 
compression trimmer and tune for minimum SWR. This does not need to be a 
pi network if you do not need any impedance transformation. If you do 
need a pi network, it can still be done externally, but it gets a bit 
more complicated.

To multiband it, run a short piece of coax to a switch which selects a 
separate LC circuit for each band. This is essentially what I have in my 
homebrew 8877 amp, although the circuitry is inside the amp instead of 
external to it. You might want two LC circuits on 80 and 160 to cover 
the whole band, depending on the Q you choose.

73, Bill W6WRT

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