I recently posted a problem with my A3S following a heavy 8 inch rainfall in
our area, and again posted asking about the Force 12 antenna that has a small
footprint, the C3SS. I am reconsidering at this point. Here is what I found
out. I applied full power to the 14 MHz band and the SWR fluctuated down! Yes
as I was applying the power at the legal limit tuning up I noticed the 3:1 SWR
reading going down. After declaring testing several times and keeping the
power level high for about a minute the SWR had dropped to 2:1. Then again I
declared testing on psk and applied full power again and the SWR dropped to
1.5:1. I again did the same and now the SWR is at about 1.2:1 on 14Mhz. I
checked the SWR on 21 MHz and have again realized 1.2:1 (with the problem in
place I could not get better than 3.5 to 1 SWR on 21 MHz), and as in the past
28 MHz about 2:1 (with the problem I had 3:1 across all of 10 meters)!!!
Okay these are the same readings I had prior to having this problem. I took
down all traps today on driven element and cleaned them and sealed them. I
replaced some of the zinc plated screws holding the trap outer covers with
stainless steel as several of the zinc ones were corroded and not making good
contact and after putting the element back together at first there was no
improvement. Still the same problematic readings.
Now that I have resonance again, I am suspecting the Van Gordon 1:1 balun up at
the antenna. Perhaps it had a loose connection through its plastic case as
some have mentioned might happen. Perhaps it sucked a little water and the
power boiled or evaporated it off.
I was about to give up on this antenna, but it is now back inside of specs as I
have set it up.
Does anybody have an idea on this. When I applied full legal limit on 14 MHz
for tune up the SWR got better and better and now is stable as it had been in
the past only better as I adjusted the outer element rods for better SWR prior
to having this problem. I have made sure all element clamps are secure by
attempting to rotate the elements after affixing the hose clamps. All is
secure.
Is it possible that the Van Gordon either lost connection through its plastic
case or had some water in it and I evaporated it?
I am open to suggestions at this point as it will be costly to replace this
system and funds are limited at this time.
Thanks in advance,
Gene Bigham KB0GU
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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