[TowerTalk] 4 square for 80

[Jim Brown]

On Sat,9/24/2016 7:15 AM, Steve London wrote:
> How much better would the performance be with a multiturn choke ? Over 
> real ground, in the presence of real, possibly interacting structures 
> within N wavelengths, isn't there a finite limit to the performance, 
> regardless of your choice of "excellent" vs. "superb" common-mode 
> chokes ? 

Hi Steve,

The primary reason for using common mode chokes in our antenna systems 
is to reduce RX noise. A string of beads choke is NOT a good choke at HF 
for the reason cited -- it's effectiveness is strongly dependent on the 
electrical length of the feedline considering it as an antenna (that is, 
considering it as a wire, not a transmission line). This is not a matter 
of "excellent" vs "superb," it is whether it is effective at suppressing 
RX noise, and whether signal pickup on the coax fills in the nulls a bit.

73, Jim K9YC