I used to install and repair buried cathodic protection systems for underground ferrous utilities. Here's the formula I used to keep the water out with direct buried connections: 1. 3 layers of 3M Scotchfil electrical insulation putty 2. 3 layers of 3M 130C rubber splicing tape 3. 3 layers of 3M Super 88 vinyl electrical tape 4. 1 layer of 3M Scotchkote liquid electrical tape For direct buried connections, this is not overkill...it's proven to work for decades when done correctly. For outdoor coax connectors I use 2 layers of 130C followed by 2 layers of Super 88 with the entire gob sealed with Scotchkote. No issues so far. Anything less...and I have problems.
You should post them. Might me entertaining. A very good friend of mine in Eastern Oregon had the same issue. Squirrels climbing his 60 or so foot tall tower and camping out of a mid height plate that served them well as an observation platform while they threw acorn shells at anyone below. Unsure if they were chewing on the coax or just enjoying the view, and not real thrilled about climbing up there to check, I offered to fly my drone (with 4KHD camera) up to have a look. I got as close as I dared and took several photos, but we say no damage to wires. Just a few fragments of acorn shells...
Here's one for you . . . I had a service call on a fire department rescue truck. The radio worked fine when the crew rolled to out the end of the district and stood by on mutual aid, in case they were needed for a call in progress in the adjacent district. The radio no longer worked when they were released from standby. A wattmeter and an MFJ-259 showed the antenna system did not tune at any frequency. An ohmmeter showed a short in the coax. Using the MFJ to sweep the line, I looked for multiples of a half wavelength to show a short, and odd multiples of quarter wavelengths to show open. I found the lowest frequency that showed a short, meaning the fault was a single half wavelength away from the connector. Using the velocity factor of half the wavelength times 0.66, I calculated the fault was about 6 feet from the radio connector. The radio was a dash-mount behind the windshield on the passenger's side of the truck cab. The coax went through the dash and firewall, and was bundled with the vehicle wiring harness across the top of the firewall to a fender-mounted antenna on the driver's side. I removed the coax, and cut it open where the meter indicated the short should be. What I found was that as the crew sat idling waiting for instructions, heat from the diesel engine's turbocharger softened the dielectric so much in the horizontally-run coax that center conductor's weight caused it to "sag" down through the dielectric to make contact with the braid. The turbocharger was at the rear of the engine, about a foot below the wiring. I ran the replacement coax under the dash inside the cab, and routed it through the firewall on the driver's side near the antenna.
This is a topic I posted on previously and didn't say too much but critters can be tough on anything left out to the weather, which ultimately our feed cables always are. I am using a direct bury coaxial cable...approx. 250 feet with about 50% buried and have had no issues for about 6 years now. Coax is Davis RF "Buryflex". Very low loss and its hooked to a Homebrew 80 meter OCF at 55 feet up. A very good performer and I usually work barefoot and I am constantly accused of running power. I used to have problems with some of the RG8 and 213 coax mostly because of the Jacket not being as good as whats being manufactured now. We used to run the coax inside a garden hose or multiples and it preserved it really well. There's nothing that's going to beat well manufactured coaxial cable, worth the investment. On a side note...insulation on any cable can make all the difference...I personally know two people who have Toyota Prius's that have been eaten by squirrels....damage to the extent that both cars were a total loss...apparently too much to repair. The insulation on the wiring is soy based plastic. Apparently tasty to the squirrels because they also ate part of the inner fender well. Welcome to the "Green" revolution. There is a sleeving available thats used on hydraulic hoses to prevent chafing and its a kevlar fabric available in various sizes...I will post the info tomorrow...also very UV resistant. Works great where the coax must run up the tower, and I think it isn't very appetizing to the critters.
The list is very long and getting the coax to fail before put into use is seen everyday. SOLDER ..... and now there are at least 50 or so points that can be brought to the surface because of soldering a connector when the ham should have been baking a cake.
Agree...poor connector soldering/crimping is another big one. I've had factory-fresh jumpers fail right out of the box...and had my own handiwork fail when I first started soldering PL259s. Back to water...the first time I actually witnessed water intrusion into coax was 1975 at my first ARRL Field Day. We held it at an old MARS shack located on top of Quackenbush Hill. All around the base of the towers was strewn more coax than I've ever seen in one place. As we were setting up antennas I inquired as to why we couldn't use the coax already in place. One of the Elmers held up the end of a cable, cut away the connector revealing the green color of the dielectric. He said that was an indication that the dielectric was spoiled with moisture and copper oxide, making it useless as a coax feed line.
Most commercial applications using coax use clamp on connectors which is eliminated several problems including impedance bumps. It took me a long time to convert but they're absolutely better than solder connectors, you can sweep them and you don't see a bump compared to a soldered connector, which that could fail. You have to have the right tools and experience to install. Once you go grip on you'll never go back to solder!! I can put a crimp on N type connector on an LMR400 in 30 seconds.
Hmmm... I bought most of my coax back in 1977, when I bought my antenna. I have some I bought in 1990 or so. Maybe I ought to put coax on my shopping list.
Well I had the 1% failure of about 200 feet of RG-213 years ago... when lightning hit My antennas and all the coaxial cable had an open circuit... I thought it was damaged the inner core but from reading up on LIGHTNING it usually burns out the outer braid....? It also melted some PL-259s & N connectors... etc... and left a large burn mark behind MY antenna switch..... VK2LEE
I have a few rotor loops of LMR-600UF that look just like that. I will say that they lasted for 10+ years before the failure.
It is rare that GOOD coax is damaged by water. Good coax begins with LDF4-50A and goes up from there. In case you don't recognize the nomenclature, that is 1/2" Heliax. Of course 7/8" Heliax and 1 5/8" Heliax are also good coax. Since Heliax has a solid outer shield of Cu, water cannot enter the inside of the shield and thus no degradation occurs. Heliax does not suck water like braided shield coax. The foam is completely sealed. It is possible to get water into one of the connectors, but that is easy to clean up. The only problem with Heliax is that you cannot use it as a rotor loop. The Cu will work harden and split.
