What happened to my coax? (Tiny holes in outside)

[safetyobc]

Hello,

As some of you know my antenna problems from this thread http://www.radioreference.com/forums/showthread.php?t=32574

I am curious to know what caused tiny holes to form in my coax? The holes were up near the top of the antenna at about 30' high and would be impossible for the antenna to be reached without my knowledge because of location and having to come inside my home to pull enough slack to let down the antenna.

Anyway, a little background. I have a Scantenna up at 30'. I was using the RG6 that came with the antenna and was pleased with it's performance. After some storms rolled through my reception went from 60 miles + to about 5 miles tops. This happened once before about a month ago but reception returned to normal after about a day. I come to the conclusion it must be moisture intrusion.

The second time it happened, I pulled the antenna down and gave it a good look and noticed that my coax had tiny holes (pin size) from the antenna connection to about 3' down from the antenna. I am nearly 100% positive no one put the holes in there. It would be nearly impossible to reach this coax without dropping the antenna and as stated above, I would know it.

The holes are all vertical holes. Like if I were standing above the antenna and punched holes downward. There are between 75 and 100 to 150 holes in the coax at random spacings.

Could it be that moisture got inside the coax and these holes are were it vented itself once the coax was heated by the sun?

Is this some sort of lightining or static discharge?

Any other ideas? I suppose these could have been there when I put the antenna up over a year ago, but I seriously doubt it because I inspected everything really well before installation.

I have ordered some QuadraShield Belden brand RG6 to replace this coax and a new balun. Any ideas on what caused this would be appreciated.

Thanks,

matt

 

[ReceiverBeaver]

Hey Matt,

I believe your station has been infected by coax beetles, which are common in your area. See www.coaxbeetles.com/maps

Uh......yeah.....so the moisture intrusion through these....uh.....beetle holes is a likely culprit. Time to replace your coax and here you have the opportunity to upgrade to some better, lower loss coax while you're at it. You'll be back to scanning more distant transmissions in no time.

 

[RevGary]

Sounds as if your cable has been victimized by some species of birds. I have seen that before and just imagine a bird grasping the coax and using a downward head motion to get at small bugs or gnats clinging to the cable. This is an issue which can be cured by using the type of coax with heavy outer metallic shielding... but is costly and impractical for all but commercial applications. Moisture will certaily enter in that manner and depending upon how agressive the birds were in trips back to get at critters living in the holes, they may have gotten all the way through the center polyfoam, close to the center conductor. If there is any outer insullation damage, the length should be replaced - not just taped up. In addition, if you have a measurement on the distance that the holes are present on the bad cable, use a length of appropriate sized rubber tubing or even garden hose over that same length on the new run to keep beaks out of your cable. Use a silicone sealant to secure the top and bottom of the tubing to the coax. Keep us posted.

 

[safetyobc]

Those are good ideas. The beetles links didn't work.

I think I will run it in some PVC pipe (or a garden hose). Very inexpensive stuff and can do it with a couple joints of pipe and a couple elbows. This should keep the coax prey away!

Thanks guys. I never thought about the birds. I bet that is what done it.

matt

 

[N9PBD]

I would agree with the assessment that it was birds picking on your coax. I work on navigational aids and radar systems, and birds wreak havoc with exposed cabling and rubber boots on antenna systems. Also, I think that Rev. Gary was pulling your leg with the coax beetle stuff....

73, Greg

 

[ReceiverBeaver]

Well now let's not let a good joke go uncredited.

The coax beetle link didn't work ?? !!!!!!!!! Well it shoud have, I made it up just a few hours ago but ya hafta allow time for the glue to dry.

I never thought about birds claws. I suppose it's possible but it sounds like really cheap-thin coax jacketing. This particular grade of RG6 that came with the antenna may be some cheaper variety.

Outdoor coax takes a beating. Freeze-thaw, wind and rain and the UV radiation is killer.

Best to change the coax now with some better stuff, low loss and heavy duty jacket. Lot's of folks use LMR 400 for scanner use. Won't go wrong with that.

good luck

 

[N8RUS]

Personally, I think you took a lightining strike.

 

[wesct]

Personally, I think you took a lightining strike.

i dont think so

a direct strike would do more damage than that!

 

[Hoofy]

If all the holes are of a uniform shape and size I would rather think that is was a manufacturing flaw in the outer coating of the coax that reacted with uv rays or other weather conditions. Maybe tiny bubbles that opened due to expansion and contraction..

 

[RevGary]

. Also, I think that Rev. Gary was pulling your leg with the coax beetle stuff....

73, Greg

GREG - That wasn't my post... my suggestions were based on fact from experience, not fiction. In any event, a little outer insullation protection is probably indicated to keep the critters away.

 

[RISC777]

Just stay away from any 'outdoor' silicone impregnated coax like cable TV companies use, squirrels love that crap for some odd squirrel reason and will chew it to shreds.

 

[safetyobc]

Replaced my coax today. Reception seems to be back where it was prior to my troubles.

I am glad too. I ran the coax through some PVC to protect it from birds, squirrels, and weather. Hope it lasts for a long time.

matt

 

[N9PBD]

Quite right you are Gary, please accept my humblest apologies. I misread the thread when posting my reply. The actual jokester was ReceiverBeaver, who I also apologize to for mis-attributing the quote.

Hopefully there are no hard feelings.

73, Greg

GREG - That wasn't my post... my suggestions were based on fact from experience, not fiction. In any event, a little outer insullation protection is probably indicated to keep the critters away.

 

[RevGary]

Nah - just a little faux pas with the reading glasses...LOL. Take care...

 

[kb2vxa]

Hi Safety and readers,

There are two possibilities, inferior coax and a lightning strike. I have heard many stories of lightning causing exactly the damage you describe so it's not as far fetched an idea as they think it is. In any case you finally found your problem, replace the coax and antenna because it may be damaged as well. Nope, it doesn't have to go into melt down, the damage can be hidden like holes in the insulating material.

BTW guys, woodpeckers don't like coax but squirrels do, I had to put mine in some armor stripped from some old BX cable once. Coax beetles? Sounds like the larval stage to me, cut worms. The beetles lay thier eggs on the antenna and the worms bury into the coax, then emerge as adult beetles which fly away to infect more antennas. That's the importance of securely wrapping the connector with tape, that's where they enter. And you though it was only for waterproofing? Another method is antenna grease, the beetles slide off before they can lay thier eggs.

 

[N9PBD]

Man, I guess April Fools lasts all month on this board...:lol:

73, Greg

 

[Myles]

Lighting?

Being a victim of lighting *related* damage, I cast my vote for that possibility.
Mine happened when clouds with high bases were overhead and a leader charge came down my dual-band Cushcraft. Didn't damage the antenna but shot through the cable where is crossed over some CATV coax. Ground in their coax must have been better than mine. It shot a small hole in the coax at that exact point where the two lines crossed each other at right angles about 15-20 feet from the antenna.
Also wound up blowing off the plastic cover on my power supply, damaged the power supply internally, blew up the cable box, damaged the TV hooked up to that box, the garage door opener, and the deep freezer (last two on oter side of house).
I was in my room with the radios when this happened and all I heard was a loud pop.
So maybe my antenna discharge saved my neighbors from a full strike.

I can't explain why your pin holes would be downward like that if they were related to static discharges though. And I would think something strong enough to do that should do some sort of damage to your equipment as well.

Maybe more related to weather, UV, and wind flexing of cable over long period of time.

(shrug)

 

[safetyobc]

I had my scanner unhooked. I always (if I the storm doesn't sneak up on me) unhook my scanner before storms and before I leave home and every night.

I guess it could have been lightining. I hope I get spared for a while now. I have invested double on this $52 antenna. I could have bought a new antenna, coax and all for what I paid to repair it, although, I think my reception is significantly better since I replaced the coax with the Belden brand.

 

[Bill2k]

My bet is on squirrels. I'm pretty sure lightning would do more damage than poking a few holes in your coax. Have you ever seen what a lightning strike does to a house or tree? Do you see any other signs of lightning damage?

BTW, if you find out you have coax beetles, get rid of them and quick. If those pesky things crawl down your coax and get into the radio, you're radio will start acting all buggy

 

[safetyobc]

It could have possibly been squirrels climbing the coax? I think I have them fixed this time though.

I just spent half the morning cutting back the PVC pipe because I had it cut too long. When I tried to rotate the antenna, the PVC would hit the roof and wouldn't allow me to rotate the antenna in the direction I wanted. You ever tried to a length of about 6" of PVC out from around coax without cutting the coax. It is a pretty neat trick!