Moisture in Coax...

[K9CCH]

I'm pretty sure that I flubbed the connections on the coax that I installed on my J-Pole, and after the first hard storm that it suffered, moisture got into the connections or the coax itself.

My question is, IF moisture got into the coax, is the whole 30 foot length ruined? Or should I be able to salvage it if I cut off say the first foot and reconnect it with a new connection?

Isn't it the NMO that's better for weather protection?

[K7SGJ]

If the N connector was put on properly, it should be watertight. Did you put any kind of sealer around it? And just out of curiosity, how did you conclude there is moisture in the coax?

[K9CCH]

Did you put any kind of sealer around it? And just out of curiosity, how did you conclude there is moisture in the coax?


Because its an SO-239 connection that's up there now. And I had intentions of going back with shrink wrap, and electrical tape but never got around to it. It weathered a severe storm and a night of rain a week or two ago and when I used the radio a day or so after, there was crackling in the signal.

ETA: I haven't used it since then either...

[K7SGJ]

Okay, I thought you put an N on it. My bad. What coax are you using?

ETA: Usually, if you get some moisture in the connector, a few day in the sun should dry it out. Worst case, replace the connector. I wouldn't be too concerned about the coax. If you decide to replace the connector, just wack off an inch or two of the coax and you should be fine. Have you tried to drop to low power, and look at an swr meter to see if it's stable? If you do have an issue with the coax or connector, or antenna for that matter, it should show up there.

[K9CCH]

LMR-400

[K7SGJ]

LMR-400

That's pretty decent coax. As long as the cable itself hasn't been compromised, Just replace the connector and an inch or so of the coax and you should be good to go. You might want to carefully check your connection from the coax to the J-pole. It may have a problem at that point which would certainly cause the noise you describe. Did you mount a UHF connector to the antenna, and then connect to that with a PL259 on the end of the coax?

[K9CCH]

Did you mount a UHF connector to the antenna, and then connect to that with a PL259 on the end of the coax?


Yup!

The Coax is brand new and there isn't any nicks or cuts or cracks anywhere that cold have compromised it, other than the end where my hack soldering job is.

I need to get a worthy soldering iron. All I have now is one of those el-cheapo $5 Weller ones with the tiny pointy tip.

[KG4NEL]

Cable jobs are one of the last bastions of ham work where big soldering guns may be a better choice. You want heat, and lots of it to prevent cold joints. I keep an old, ugly Weller with my Field Day stuff just for that reason, although to be honest at home I'm usually too lazy to do it and buy pre-assembled lengths instead :twisted:

[K7SGJ]

Yup!

The Coax is brand new and there isn't any nicks or cuts or cracks anywhere that cold have compromised it, other than the end where my hack soldering job is.

I need to get a worthy soldering iron. All I have now is one of those el-cheapo $5 Weller ones with the tiny pointy tip.

That being the case, I would definitely check the connection at the connector/J-pole junction. You need a lot of heat to make that a reliable connection. A torch might help you out if you are careful with the center of the SO 239 connector. And, as NEL noted, a large gun or iron is necessary to get a solid connection of the braid of the LMR400 to the barrel of the PL259. Perhaps you can borrow one if you don't have or can't get one right now. And once done, I would wrap the connection with some of the rubber tape like electricians use for wrapping conduit below grade. That black gorilla snot made to weatherproof connectors works well, but is a pain in the ass to remove if necessary. Of course, vinyl electrical tape will work in a pinch, too.

[KA9MOT]

The symptoms of coax with water in it is high SWR. Crackling in your signal can be caused by a bunch of different things. It has been my experience that water runs downhill and both times I've had water in my coax, the coax sucked it up and I found it at the bottom of the hill.

Buy, Borrow or steal a better soldering iron. This is a worthy investment if you'll be soldering your own connectors on.

http://www.homedepot.com/p/Weller-100-140-Watt-Soldering-Gun-Kit-8200PKS/100085564#.UjClG8ZHQXc

I've had a Weller WP-35 iron for my bench since 1993. But I don't use it for coax work. I do use a Weller Portasol P-1K for indoor coax solder jobs. Tips are hard to find and getting expensive.
Hope this helps.

[PA5COR]

80 watt soldering iron from Antax the 35 watt is decent but the extra heat from the big one does itt in seconds cool it off and be done.
After mounting the connector outside i use selfamalgamating tape and never look back.
I use that stuff since 37 years and removed it from connectors that had been out here in heat cold snow salty conditions for 20+ years and kept the connectors dry and as new.

Wind it after stretching with 50% overlap ober connector and the connector the plug goes in.
Stretch it doing so, the last 1 or 2 inch don't stretch just stick it to the underlayr that prevents the end from getting loose and start flapping in the wind ( don't ask how i found that out) ;)
Cables used here are the Exoflex 15 very low loss coax 15 mm outside diameter and € 5.50 a meter.... i have 80 meters up in 3 lines.
That is $ 550.00 in dolars the N connectors are 12 Euro a piece....

[K9CCH]

The symptoms of coax with water in it is high SWR. Crackling in your signal can be caused by a bunch of different things. It has been my experience that water runs downhill and both times I've had water in my coax, the coax sucked it up and I found it at the bottom of the hill.

Buy, Borrow or steal a better soldering iron. This is a worthy investment if you'll be soldering your own connectors on.

http://www.homedepot.com/p/Weller-100-140-Watt-Soldering-Gun-Kit-8200PKS/100085564#.UjClG8ZHQXc

I've had a Weller WP-35 iron for my bench since 1993. But I don't use it for coax work. I do use a Weller Portasol P-1K for indoor coax solder jobs. Tips are hard to find and getting expensive.
Hope this helps.


hell yes! And I just won a HD gift card this afternoon at a 911 appreciatin event!!

[W5BRM]

Not to be sounding like a troll... seriously not... but WTF is a 9/11 APPRECIATION event? Did whatever business or corporation that awarded it to you APPRECIATE the deaths of 3K people? It absolutely SICKENS me about these asshole corporations and businesses who attempt to profit from mass murder and national tragedy. Sorry dont mean to derail the thread.... Dont mind me, just feeling the losses even now... and no im not trashing you or trying to be derogatory or negative toward you but its just plain disgraceful that this sort of crap happens. I know this part of the forum isn't for really ranting but I HAD to say something... it angers me THAT much... and i think im a pretty stable guy...


Anyway, rant over... got way too much to say and this aint the place for it.

I now return this thread to original topic

[K9CCH]

I'm a 911/police dispatcher, and our emergency management district does these events every year. Sorry, didn't even think about it coinciding with the date, but no, it wasn't an appreciation of 3k victims.

[KG4CGC]

Take down the coax and test it for a short.
Just to be on the safe side, wack off about 4 to 6 inches and put a new connector on it. There is silicone sealer tape that sticks to itself but has no adhesive. This stuff is awesome but can get pricey if you don't shop around. Hardware stores have it and sometime the Evil Empire carries it. Try RS if all else fails.
Cushcraft included silicon goop with some of their antenna kits. 10 years later and that stuff is still fresh like the day I applied it. The goop goes on the threads after you has the coax almost all threaded up on the SO-239. Then you finish screwing it on a couple or three turns and you're sealed from moisture and corrosion on that front.
I've recently become a fan of heavy duty all weather crimp on F connectors for 75 ohm coax. RG-6Q is my choice for scanner and stuff of that nature. It is also more compatible with small antenna amplifiers that you can buy just about anywhere for cheap.

[KA9MOT]

I've been known t use RG-6 with the weathertight crimp on connectors as well. It works very well and is low loss. I've used it for HF and VHF. Yes, you will never have better than a 1.5:1 SWR, but that will cause no harm to your signal or rig.

[W5BRM]

I'm a 911/police dispatcher, and our emergency management district does these events every year. Sorry, didn't even think about it coinciding with the date, but no, it wasn't an appreciation of 3k victims.

Ah OK. Misunderstanding then. Still There are other business who are doing that

http://www.huffingtonpost.com/2013/09/10/9-11-golf-special_n_3899897.html?ir=Small+Business

http://money.cnn.com/2013/09/11/technology/social/att-9-11-tweet/index.html

And all those who are SELLING memorial trinkets etc..

But anyway I'm really SK now...lol

[K0RGR]

Crackling in the received signal does indicate an intermittent connectin someplace, not so much water. I've never had a problem with water in LMR400. But a poor connection - maybe a poorly soldered shield? Antennas with fiberglass bodies sometimes develop intermittents between sections that will crackle in the wind.

[HUGH]

Moisture in your coax can cause corrosion, especially if the screen contains aluminium foil, aluminised mylar or even copper. It will still work well for a long while if you can dry it out, but if not, aluminium foil will disintegrate over time. Here speaks another one who uses RG6, CT100 or anything stocked at the local electrical wholesaler.