Antennas Direct 91XG Water Infiltration of Balun?
 

We had 4 inches of rain in our area overnight and today I am experiencing low signal strength on UHF stations. My antenna system is a 91XG for UHF and a Y10713 on VHF combined with a UVSJ and then running 50 ft to a distribution amp. Following the heavy rain I have experienced no decrease in signal strength on the VHF side but all signals are down on the UHF side. The weakest stations are completely gone. Several stations that were not at max strength before but had good quality are now weaker and have dropped in quality.

Has anyone ever experienced water infiltration of the balun on the 91XG? It is about the only point in the system where I would have any concerns about water causing a problem. Everything else is very well sealed. If water infiltration is the problem, I would expect it to clear up after a few days of nice weather dries it out.

We have one every once in a while.

As it turns out, when the factory changed the mold for the enclosure a few years back (when they transitioned from a traditional ferrite matching transformer to the PCB version), they forgot to include the weep holes in the new enclosure.

Call in during business hours and tell customer service you need a new "91XG Balun Assembly" and tell them specifically to be sure that the replacement must have weep holes drilled in the case before the replacement ships out. Depending on who you get, they may or may not be clear on what you mean so just tell them to include that in the message to the person who ships out warranty replacement parts. That person does know the routine.

If you want to drill out the enclosure yourself, it's two small 1/16" holes on the side of the plastic enclosure opposite the balun element. When reassembling the balun assembly to the boom, put a gob of silicone sealant into and around the captive nut of the enclosure, then attach it back to the boom using the original screw.

You may need to replace the coax from the balun as it might have turned into a water line.

Thanks for the info ADTech. I spoke to Steve today. He had never heard of that problem but put me on hold, checked it out, and came back on the line and said he would be shipping a new one out to me as soon as they drilled the weep holes. Great customer service!

I received the new balun assy and had planned to install it today. However 45 degrees is a little chilly and makes raising and lowering the telescoping mast a real chore (six decade old arthritic hands don't work well in the cold!)...think I will wait for a warmer day! In the meantime, evidently the existing balun has dried out and reception has returned to normal. I will make sure everything is well sealed around the mounting hole when I do get a nice day to install it.

Be sure to use a true 100% RTV silicone, such as GE and NOT that siliconized latex caulk.
I have seen the siliconized latex version corrode metal, including turning PCB copper a bluish green.

Be generous w/ the gob =d

Hello,

Where is the location of the weep hole(s) supposed to be located? I lost a balun and suspect this to be the cause.

See post #2, I described where I drill them. A hole in each of the corners of the bottom of the housing that are closest to the F-connector. Do not drill in the corners directly under the driven element.



You can do this "in the air", if you choose, but you might get wet!



If you need a photo, let me know and I'll post one up here.

Thanks for the clarification.

Well Hello there antenna Direct 91x,come's with a life time
On all parts,shipping RIGHT to your house free.
They stand behind their ANTENNAS DIRECT 91xg.
Call asap you will receive a new one.
And on the new one use some black RTV
On the seem.And it will never happen again
Good luck!

Seeing how we're on the subject of 91XG's, though it was a couple years ago I am experiencing an anomaly.

My original XG was on the mast for 4 years without the water relief holes drilled.

I brought it down to repair the reflector I decided to try some DXing and to pair it with another 91 XG. But first, I decided to test them separately and I'm glad I did.

At first I thought it was a ladder blocking signal under the right side so I moved them over to my other mast. Yes, there is still a ladder under the antennas. This one is much lower under the array and more equal between the two antennas.

There's quite a difference in signal strength between what should be equal signals.


http://forum.tvfool.com/attachment.p...1&d=1589302247

http://forum.tvfool.com/attachment.p...1&d=1589302267

Some updated testing results.
 

I tested my older XG91 vs. my HDB91X. I wish I would have compared it to my newer XG 91.

http://forum.tvfool.com/attachment.p...9&d=1589461345

Balun Photo
 

Balun photos... at first they didn't show, do they show now?

http://forum.tvfool.com/attachment.p...1&d=1589548339

http://forum.tvfool.com/attachment.p...1&d=1589548445

http://forum.tvfool.com/attachment.p...1&d=1589548474

http://forum.tvfool.com/attachment.p...&d=1589548507l

http://forum.tvfool.com/attachment.p...1&d=1589549005

Spectrograms old 91XG versus new 91XG
 

So, Just for the hell of it, I combined the two and scanned. Later I came home and rescanned. So, having two unevenly matched antenna is detrimental, and it appears that a clear sunny sky is better than overcast.

http://forum.tvfool.com/attachment.p...1&d=1589480511

Just before sunset, I scanned the UHF spectrum and then a few hours later I scanned again:

http://forum.tvfool.com/attachment.p...1&d=1589480523


New Vs. old yesterday:

http://forum.tvfool.com/attachment.p...1&d=1589480539

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...

I resurrected the thread simply because I hate to see a bunch of different threads about the same subject. So, you never got around to putting the other one up? I wondered what happened. But I know what you mean, if it ain't broke you don't have to fix it.

Antennas Direct has agreed to send me another balun, which is very cool. As soon as it comes in, I'll put it on my old antenna and see what happens and report back.

I've overcome my fear of heights lately when I bought a 22 foot step ladder and put it up on my roof. I know my neighbors think I'm nuts.

http://forum.tvfool.com/attachment.p...1&d=1589547778

Oh my gosh! I get woozy just looking at that photo!

Two 91 XGs different results. Baffled!
 

[[B][SIZE="3"]Well, I got the brand new Balun from Antennas Direct yesterday. No change, the patterns were about the same. I swapped coax cables no change. I put the old 91XG balun on the new 91XG and that didn't change. I even swapped the reflectors.

The reflectors are somewhat flimsy and even the new ones seemed to be bent. Still didn't make a difference.



When I assembled the new 91 XG next to the old one they appeared perfectly the same. The directors are reversible, but I use them in the hi performance mode. On this particular set of reflectors I noticed some misalignment.
http://forum.tvfool.com/attachment.p...1&d=1589654497

http://forum.tvfool.com/attachment.p...1&d=1589654093

http://forum.tvfool.com/attachment.p...1&d=1589655371


http://forum.tvfool.com/attachment.p...1&d=1589655371


http://forum.tvfool.com/attachment.p...1&d=1589655371



http://forum.tvfool.com/attachment.p...1&d=1589655371

http://forum.tvfool.com/attachment.p...1&d=1589655664


Just for fun and nothing better to do, I scanned the two Antennas combined and came back a few hours later and rescanned, just to prove the signals do change in strength:

http://forum.tvfool.com/attachment.p...1&d=1589655769

Tell me of the "hi performance mode" you speak of. I am not familiar.

By the way, that photo of you standing on top of the very tall stepladder on top of your roof just scares the crap out of me! I almost got dizzy and fell out of my office chair while looking at it!

I'm surprised that those pictures do that to you, but they can. I have a weird fear of heights myself. I can go up in the tallest buildings in the world just fine but looking down makes my legs buckle. They have a glass floor in the CN Tower. I was scared to walk across it. They now have one in the Willis (Sears) Tower and lean out windows in the John Hancock building both in Chicago.

Tim, I'm glad I saved the instructions. Here's where they describe the way the directors go on performance mode. Well it says "performance may be improved by facing the metallic side of the director elements towards the transmitters"

http://forum.tvfool.com/attachment.p...1&d=1589938343

http://forum.tvfool.com/attachment.p...1&d=1589938935

I made these videos back in 2016 first set up my antennas.
https://www.dropbox.com/s/qhrya79180...ennas.mp4?dl=0

https://www.dropbox.com/s/4jvdkuw1wr...20002.MP4?dl=0

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.

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.

Balun Photo ?
 

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

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

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 :)