Antennas Direct 91XG Water Infiltration of Balun?

[bobsgarage]

Originally Posted by Tim

Thanks for sharing Bob. You certainly have a good memory for details. Evidently I read those instructions 5-1/2 years ago when I installed my antenna because all of the elements have the metallic side facing the transmitters.

By the way, what are you using for your spectrum scans?

Hi Tim, that's the same instructions I saw 4 years ago when I put my original 91XG together. They've always used the Terrestrial Digital name on those instructions.

I have had some contact with AD & ADTech, but he's been pretty busy and referred me over to AVS ask for help.

Antennas Direct warranty dept. shipped a new Balun, but no change in the signal patterns. I think the problem with the two antennas being different is just the way it is and I will have to buy another and hope it matches the new one.

I am, using RTL/SDR software with a Chinese USB dongle. Pete Higgins recommended it here and on the the old Hi Def forum. It's slow though, but I get great patterns.

[Tim]

Originally Posted by Tim

Funny that this thread resurrected itself. To follow up on my original post, I received the new balun from Antennas Direct in Jan 2015, but never got around to installing it. The water intrusion in the old balun evidently dried up while the balun was being shipped and I had no more problems...until this spring. We had a lot of rain this spring and the problem resurfaced...I've had really crappy UHF signals for over a month now. I have the new balun assy still sitting on a shelf in my office, so now I just need to work up the energy to pull down the antenna and install it. I just hate dealing with ladders, roofs and heights in general...anything more than three feet off the ground makes me queasy...

Well, I finally got around to installing the replacement balun that Antennas Direct sent me back in 2015 and all is back to normal with my UHF channels. As ADTech surmised the original balun did not have weep holes to allow moisture to escape. As Stereocraig suggested I used RTV sealant in the mounting hole when attaching the balun back to the mast to help keep water from getting in there in the first place.

I opened the balun and it looked pretty nasty and there was a good bit of corrosion. I am surprised that after the initial problem that it worked another 5 years before I finally had to pull it down and replace it. My son came over and helped me with the project...he is much more agile than me on a roof.

[bobsgarage]

Glad to hear you finally got that done and that you had some improvement. Did you take a photo of the old balun?

[rickbb]

Originally Posted by Tim

I am surprised that after the initial problem that it worked another 5 years before I finally had to pull it down and replace it.

And I thought I was procrastinating waiting 4 months to put up my 751.

[Tim]

Originally Posted by bobsgarage

Glad to hear you finally got that done and that you had some improvement. Did you take a photo of the old balun?

Actually, yes I did. As you will note, my hamfisted approach to opening the balun resulted in a broken PC board. The PC board itself looked in good condition (except for the break-LOL!) The coaxial connector also looked good. I think the main problem was the corrosion at the connection to the driven element.

Makes me wonder what effect on performance would occur if the PC board balun was replaced with a ferrite core balun.

[bobsgarage]

Originally Posted by Tim

Actually, yes I did. As you will note, my hamfisted approach to opening the balun resulted in a broken PC board. The PC board itself looked in good condition (except for the break-LOL!) The coaxial connector also looked good. I think the main problem was the corrosion at the connection to the driven element.

Makes me wonder what effect on performance would occur if the PC board balun was replaced with a ferrite core balun.

Whoa! That is bad! All mine are drilled now...All 7