Hi all,
I'm in the process of cleaning up/refurbishing a tribander for the winter
season. I cleaned out all the traps, used new h/w where needed etc.
Put the thing back together and in the air. It worked great for about a
week till we had some rain.... SWR on all bands shot up to over 3:1.
Took the ant. back down and went thru it again. I noticed the "old"
Noalox in the tubing joints was somewhat caked on contained alot of
moisture.
When I took the ant down, I put the 259B on it and found the resonent
freq on all bands about >800kc high on all bands, which is about 100kc
higher than when up in place and the SWR went crazy.
I started cleaning the grey gunk from the joints with great difficulty.
Didn't really know what to use to clean up the joints and went rummaging
around the garage... I ended up using Ether (AKA engine starting fluid).
This stuff on a paper towel, easily cleaned up all the tubing joints like
new...
Used the paper towel wrapped around a round dowel to clean the inside of
the larger tubing. The tubing came out really clean/shiney and with no
residue.
I did a dry-fit of the driven element with proper dimensions and the 259B
said the Resonant freq was right on where I wanted it. The res. freq
should
drop a bit when the antenna is in the air.
Now that I've put you all to sleep, here are a couple of questions:
1. Why did the moisture mix with the Noalox?
2. Did the moisture cause an "insulating" barrier causing the SWR
problems?
3. What does everyone use to clean out the tubing joints? (Any cleaning
solution in a pinch?)
4. What are the disadvantages of "dry-fitting" tubing joints and using
the antenna
as is? I have no problem taking the antenna down every couple of
years for maint.
Any constructive guidence would be appreciated
73 es DX
John K1RC
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