Eric ,I had a problem several years ago with my TH7dxx. High swr only on 15
most of the time and after rain 10 would be effected and in time 20 too. After
a good dry out, this took days, things would return to normal. At first I went
the way of replacing baluns with no effect. Take a look at
http://w8lky.org/images/06.jpg this is the picture of one trap, you will see
what caused my high swr. The traps became full of insects and grass. When wet
weather came this caused the packing in the trap to short out the trap causing
the swr to shift. Wet is something we in Ohio are used to. At 70 feet you
would think critters would not nest in a trap. Why did they like 15 meter traps
better that the 20's? Someone here on the reflector might know! The process of
replacing baluns, feed line and finally taking down the antenna took me months
but after blowing out all the traps everything was back to normal. I did
experience the same problem again 4 years later. The solution was replacing
the TH7 with a SkyHawk, no traps.
Every one is probably asking didn't he have the drain holes down? Yes I did,
the trap full of junk soaked up water like a sponge.
Cant say this is your problem but it raises a red flag here.
Good luck
John
K8LN
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|
