[TowerTalk] Stubs and Reactances in parallel

[Richard (Rick) Karlquist]

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