On 6/24/2020 5:41 PM, Jim Brown wrote:
Steve,
Wes's question and your reply yields the key. You're switching the
resonance of the antenna, but not the stub. Take a look at the plots in
http://k9yc.com/Coax-Stubs.pdf ; which I did by point-by-point
measurements before I had a VNA. The stub is only a very high impedance
at resonance, and the Q is too high to cover as much of the band as
you're attempting to cover. Note from my app note that the location of
You can get a substantial improvement in bandwidth by replacing the
stubs with lumped element equivalent tank circuits. Try it on Simsmith
and see.
73
Rick N6RK
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