Topband: 160m Vertical

Jim Brown jim at audiosystemsgroup.com
Fri May 15 14:12:56 EDT 2020


On 5/15/2020 8:27 AM, donovanf at starpower.net wrote:
> A more reliable approach is a tuner in your shack. The extra coax
> cable loss from elevated VSWR is insignificant on topband.

I strongly agree with this.

Another suggestion. Do your best with what you can rig, using as much 
top-loading as practical rather than base loading. Sweep the feedpoint Z 
with a good analyzer, export the data to SimSmith, do a TDR of the 
feedline to find it's electrical length, and compute the match. I 
recently did that for W6GJB's new 630M antenna, and came up with shunt L 
at the base of the antenna and series C in the shack. Every antenna is, 
of course, different.

73, Jim K9YC








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