EZNEC Rohn 25 top loading 115' Rohn 25 4 spoke top hat, 66" x 0.500" tubing SWR in a 30 ohm system (match 30 ohms to 50 ohms)
1.800 MHz, 2.2:1 1.900 MHz, 1.2:1 2.000 MHz, 2.2:1 KH6AQ (formerly WX7G) On Fri, May 15, 2020 at 8:13 AM Jim Brown <j...@audiosystemsgroup.com> wrote: > On 5/15/2020 8:27 AM, donov...@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 > > > > > > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector