Scott Robbins wrote:
>
>
> I have been doing some work on a SO2R contest station and have only
> recently come to the question of using band stubs for nulling out
> unwanted signals. I have noted that at 500 watts I don't really have
> a problem, but at 1500 watts it starts to present a little bit of a
> dilemma on a few band (but not all) combinations.
>
> I understand the generalities of using stubs, but this is one question
> I don't know the answer to: is right at the output of the amplifier
> the only spot the stub is useful/usable? I use a couple of mono-
> banders on a remote coax switch that could easily have stubs on T
> connectors added at the switch. I have seen nothing to indicate this
> is indeed possible, but wanted to inquire with the thought pool
> here first.
>
> --Scott, W4PA
sure, the stubs can be anywhere along the feed line. they are most
commonly at the amp output in m/m stations because that is an easy
place to put them when the amp will only be on one band.
check out:
http://www.berkshire.net/~robbins/technote/techref.html#filters
for some notes on stubs, including the advantages of pairs of
stubs.
--
David Robbins K1TTT (ex KY1H)
k1ttt@berkshire.net or robbins@berkshire.net
http://www.berkshire.net/~robbins/k1ttt.html
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