[TowerTalk] TH6 SWR curves

[Dennis W0JX]

Bob:
The TH6 is a great antenna if it is up high enough and the proper settings are used:

1.) There are three settings: CW, Low Phone, and High Phone. The best overall setting is Low Phone which will give you decent curves over the CW band and a good portion of the phone band;

2.) The TH6 hates low heights. It is susceptible to considerable ground effect and detuning from surrounding objects  if mounted below 50 feet. Your SWR curves appear to be very low. For example, my TH6 which sits on an 80 foot tower has its lowest SWR point around 21.180 ( I deliberately lengthened the driven element a tad, normally it is higher);

3.) Normally, the minimum SWR on 15 is higher than the two other bands. My minimum is about 1.4 to 1 at the end of 180 feet of RG-213. The curves will be narrower with shorter lengths of coax;

4.) Use the very best current balun you can afford or make a coax choke balun out of coax. I have blown out my share of BN-86's and switched to the BN-4000. Even that developed a loose connection internally and had to be rebuilt.

I have had my TH6 since 197 and on five different towers 60 to 80 feet high. Today, the YI9 in the log on 20 with it. It just needs to be assembled correctly and taken care of.

73, Dennis W0JX/8
Milan, OH Birthplace of Thomas Edison
www.tomedison.org