P.S. If your vertical has a good set of radials, you will see about 35 Ohm feedpoint impedance. You may want to wind your own unun using Jerry Sevick’s cookbook
http://www.introni.it/pdf/Amidon%20-%20Transmission%20Line%20Transformers%20Handbook.pdf or buy a readymade 35 to 50 Ohm unun from balundesigns.com The third option is to build a coax transformer per PA0FRI. Rudy N2WQ Sent using a tiny keyboard. Please excuse brevity, typos, or inappropriate autocorrect. > On Dec 5, 2020, at 8:37 AM, David Aslin G3WGN <da...@aslinvc.com> wrote: > I'm building a contest station and the time has come to make a choice of > 160m TX antenna. Looking at DXE Thunderbolt I note that the capacity hat > extends to a significant distance down the vertical section. It's my > understanding that will shield some of the radiation from the upper part of > the vertical. Alternatives like a vertical tee would not have this issue. > Is my understanding correct? > > I'm considering a commercial antenna as high strength telescoping antenna > tubing is unobtanium in UK. My QTH is an exposed windy location so strength > matters! > 73, David G3WGN M6O > > > > Sent from my Galaxy > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector