waterproofing an LNB connection

[rmccolman]

Hi guys -- I'm installing my new GEOSATPro 1.2m dish, along with a SL1PLL LNB, and I'm scratching my head a bit on how to waterproof the RG-6 cable connection. The LNB didn't come with any kind of waterproofing boot. It also doesn't have any kind of drip shield extending out from the body of the LNB to protect the F-connection from dripping rain water. I have some high quality compression-style RG-6 F-connectors, but they don't have an internal O-ring to seal out water between the threaded female nut and LNB's F-connector.

I've not really run into this issue previously, as all the satellite LNBs and OTA antennas I've owned/used up until now have had some sort of boot or drip shield to protect the connection. And although I've seen some F-connectors at some point in the past that have an O-ring inside the female connector nut that screws onto a male F-connector, my searches so far haven't turned up anything that appears to have an O-ring inside that nut -- even F-connectors that claim to be rated for outdoor use. (In those cases, such connectors have an O-ring around end that the cable inserts into, but not at the threaded nut end.)

I've read about using "Self Amalgamating Tape" to waterproof coax connections, but that seems to work primarily on cable-to-cable splices where there's lots of room down the cable past the splice point to acheive sealing action. It's difficult for me to imagine that there's enough exposed thread surface on the male connector protruding from the LNB for the tape to form an adequate seal.

I've also read online where someone had used some dielectric grease on/in an LNB connection to seal out water, but I'm a little leery of using that as an option for this application, as I'm not sure how effective it would be -- also I'm wondering what effect the grease could have on the tiny center-conductor connection should any of it get in there, especially with the signal path being fairly low-current (even though dielectric grease IS designed for higher-current electrical applications, such as automotive light bulb contacts, etc.)

Any insights that any of you could provide to help me waterproof this LNB connection would be appreciated.

Thanks - Richard

 

[primestar31]

Coax-Seal, hands down. (1 ROLL) Coax Seal Moisture Proof Sealing Tape 1/2" x 60" | eBay

 

[FTA4PA]

Hi guys -- I'm installing my new GEOSATPro 1.2m dish, along with a SL1PLL LNB, and I'm scratching my head a bit on how to waterproof the RG-6 cable connection. The LNB didn't come with any kind of waterproofing boot. It also doesn't have any kind of drip shield extending out from the body of the LNB to protect the F-connection from dripping rain water. I have some high quality compression-style RG-6 F-connectors, but they don't have an internal O-ring to seal out water between the threaded female nut and LNB's F-connector.

I've not really run into this issue previously, as all the satellite LNBs and OTA antennas I've owned/used up until now have had some sort of boot or drip shield to protect the connection. And although I've seen some F-connectors at some point in the past that have an O-ring inside the female connector nut that screws onto a male F-connector, my searches so far haven't turned up anything that appears to have an O-ring inside that nut -- even F-connectors that claim to be rated for outdoor use. (In those cases, such connectors have an O-ring around end that the cable inserts into, but not at the threaded nut end.)

I've read about using "Self Amalgamating Tape" to waterproof coax connections, but that seems to work primarily on cable-to-cable splices where there's lots of room down the cable past the splice point to acheive sealing action. It's difficult for me to imagine that there's enough exposed thread surface on the male connector protruding from the LNB for the tape to form an adequate seal.

I've also read online where someone had used some dielectric grease on/in an LNB connection to seal out water, but I'm a little leery of using that as an option for this application, as I'm not sure how effective it would be -- also I'm wondering what effect the grease could have on the tiny center-conductor connection should any of it get in there, especially with the signal path being fairly low-current (even though dielectric grease IS designed for higher-current electrical applications, such as automotive light bulb contacts, etc.)

Any insights that any of you could provide to help me waterproof this LNB connection would be appreciated.

Thanks - Richard

There are several choices. I've been using this for almost a decade with no issues. Just stretch it a bit making sure you get it completely wrapped around the stub that sticks out from the lnbf. It fuses to itself and I have never had water intrusion on a properly wrapped connector. Easy to remove as well - just carefully score it with a sharp blade and it peels right off.

https://www.lowes.com/pd/3M-Temflex-2155-Rubber-Splicing-22-ft/3129711

I'm sure there will be other suggestions but this is what works for me. Good luck!

 

[Inclined Orbit]

I'll throw in my 40+ year experience with two way radio and satellite and it all depends on where you live and how long you want the connector to be waterproof. In So Cal I was responsible for installing and maintaining dozens of antennas and probably 100+ LNBs at a DirecTV uplink center. Since our LNBs would probably be touched or swapped out in less than 5yrs, a couple of layers of Scotch 33+ was more than adequate. I actually have connections on big two way radio repeater antennas that were wrapped with a few layers of Scotch 33+ and they looked like new when removed 25yrs later. But this is in sunny So Cal and I wouldn't do that in Wisconsin, I would use something more like the 3M Temflex mentioned above for home use or for a limited time on a commercial install. I do have some personal equipment outdoors near Boston that has 3 layers of Scotch 33+ and its been fine over the last 10yrs but I will probably take those apart and re wrap next trip there.

For a permanent connection where you don't want to worry about it for the rest of your life, the two way radio industry has a standard using two types of electrical tape and a sheet of thin, sticky tar like material we call monkey snot. If you look at any unattended mountain top repeater site you will see lumps in the coax where cables are joined and at the actual antenna and the lump is shaped like a football. Rather than describe the process, here are instructions from one company that sells the connector waterproofing kits. https://www.commscope.com/globalassets/digizuite/52706-7634613-a.pdf

The reason for the first layer of tape is because if you put the monkey snot right over bare cable and connectors, that's it, you will never get the stuff off and you basically end up cutting the connector off. With the first layer of tape the connection will easily come apart and 30-40yrs later it will still as good as the day you first wrapped it. Very few satellite installs need this but if your in an area that is constantly wet and freezes in the winter then bakes in the summer and you want it permanent, this is the way to go.

 

[rmccolman]

Thanks for the suggestions, guys.

News update -- I see a further complication with this (using the tape), now that I've connected the cable to the LNB. The issue is that the nut on the cable's female F-connector tightens to within only about a fingernail's thickness -- roughly 1 mm -- of the LNB's plastic housing where the male F-connector comes out. I don't see how I could get enough of the tape seated against the tiny bit of that male F-connector on the LNB to contact and seal the joint between it and the cable connector's nut. (If there was at least 4 or 5 mm or so of exposed male F-connector, it might be possible to make the tape work.)

Wrapping the tape that close would be further complicated by the fact that the flat plastic area where the male connector comes out of the LNB's housing is recessed a few millimeters into an otherwise round LNB housing. See this pic:

https://hypermegasat.com/all-products/ols/products/geosatpro-sl1pll-standard-single-phase-lock-loop-ku-lnbf

The tape could seal the cable's connector from the nut down to the cable, but it's difficult to see how it could create much of an effective seal between the nut and the tiny bit of the LNB's male connector that's not covered by the nut. When I sent my initial email, I hadn't yet connected the cable to the LNB, so I didn't realize how this geometry would play out.

I suspect I may have to fabricate some sort of small plastic rain shield out of a PVC plumbing fitting (or something similar) to fit over the F-connector end of the LNB so that part of the fitting will hang below the connector to minimize potential rain exposure at the connection point. Maybe that along with using a bit of dielectric grease in the connection joint.

The good news is that the 1.2m dish is up and running, and I can see a major improvement in signal quality over my re-purposed Orby dish when dialing the receiver to the weak NBC MUX channels on 103W on a cloudy day like today.

Richard

 

[ZetaMale]

We get very little rain or snow in my neck of the woods but I use compression connectors that are suppose to be waterproof. I haven't had any issues with waterlogged connections. They're a bit of a pain to put on correctly but I think it's worth doing. Other than that, a coax seal would be the thing to do. The feedhorn cover should help but then you run the risk of having wasp nests under the cover.

 

[Inclined Orbit]

Thanks for the suggestions, guys.

News update -- I see a further complication with this (using the tape), now that I've connected the cable to the LNB. The issue is that the nut on the cable's female F-connector tightens to within only about a fingernail's thickness -- roughly 1 mm -- of the LNB's plastic housing where the male F-connector comes out. I don't see how I could get enough of the tape seated against the tiny bit of that male F-connector on the LNB to contact and seal the joint between it and the cable connector's nut. (If there was at least 4 or 5 mm or so of exposed male F-connector, it might be possible to make the tape work.)

Wrapping the tape that close would be further complicated by the fact that the flat plastic area where the male connector comes out of the LNB's housing is recessed a few millimeters into an otherwise round LNB housing. See this pic:

https://hypermegasat.com/all-products/ols/products/geosatpro-sl1pll-standard-single-phase-lock-loop-ku-lnbf

The tape could seal the cable's connector from the nut down to the cable, but it's difficult to see how it could create much of an effective seal between the nut and the tiny bit of the LNB's male connector that's not covered by the nut. When I sent my initial email, I hadn't yet connected the cable to the LNB, so I didn't realize how this geometry would play out.

I suspect I may have to fabricate some sort of small plastic rain shield out of a PVC plumbing fitting (or something similar) to fit over the F-connector end of the LNB so that part of the fitting will hang below the connector to minimize potential rain exposure at the connection point. Maybe that along with using a bit of dielectric grease in the connection joint.

The good news is that the 1.2m dish is up and running, and I can see a major improvement in signal quality over my re-purposed Orby dish when dialing the receiver to the weak NBC MUX channels on 103W on a cloudy day like today.

Richard

Scotch 33+ is very flexible and as you spool it off the roll you can use a finger to stretch it and transition from the connector up the wall of the LNB housing slightly. You could also prep the LNB with a very small fillet of sealant at the connector/housing junction and let that cure before attaching the connector and taping it all up. Or you could attach the cable with connector, tape it up then apply some sealant to the tape/LNB housing junction last.

 

[Comptech]

I use snap and seal compression connectors, and a dab of silicone dielectric in the connector. Never had a problem here in the Carolinas, or when I lived in Florida.

 

[Inclined Orbit]

I use snap and seal compression connectors, and a dab of silicone dielectric in the connector. Never had a problem here in the Carolinas, or when I lived in Florida.

Whenever I had a say in purchasing connectors I always went with T&B Snap-N-Seal. DirecTV had an "official" brand of connector but I preferred T&B universal types (red version) that would work with single or quad shield and they had internal O rings. I experimented with Stuff brand dielectric grease but decided not to adopt it for our uplink center use due to the mess and it dries out causing you to clean the crumbs out of the connector whenever you had to swap equipment out.

Two or three wraps of Scotch 33+ is fine for most of the outdoor F connections you will encounter on satellite equipment.

 

[mr_rye89]

I got some of that "Miracle Wrap" self fusing silicone crap at Lowe's this morning that I might use on the C band dish once I have the coax how I want it. My new Amiko 8x1 Disecq switch is going in one of those 6" x 6" x 4" Cantex boxes sometime this weekend. Rain is rare here but if there's a monsoon this year it'll really pour.

 

[Lone Gunman]

Heh, you guys are going to laugh at me, BUT, I've used those "screw on" RG-6 coax cable connectors forever on all 3 of my satellite and OTA TV systems and I seal those screw onto the cable connectors packed with PETROLEUM JELLY along with the same stuff packed in the connections to the "F" fittings that are outside. When I hand tighten those fittings the pertoleum jelly squishes out of all the contact points and water seems to have a hard time displacing it. I can't remember the last time I had a water problem with those and we get our share of rain and snow here where I live.

Just saying..................

 

[rmccolman]

Same general concept as using the dielectric grease.

Looks like several options to explore from all the responses. I'll mull it all over.

Thanks - Richard

 

[arlo]

Yaaa.....Flex Seal. That's what I've used on F, N, PL connectors out in the elements for a few years now.
Tighten the connector down to the last few threads. Give it a spritz. Tighten it down the rest of the way. Let it goo up. Give a another spray or two all around the connection and cable. You're golden.
I just put a run of LMR400 to replace 9913 that was up for 6-8 years. I guess I didn't really have to.
No water intrusion. All connections were still shiny under the Flex seal. Cutting the 9913 open a few inches back from the N connector showed nice, shiny copper. That's after 6 years of rain and snow and 30 below.
Plus, you can make a boat from it and go fishing. Try that with Coax-Seal!

 

[Comptech]

Whenever I had a say in purchasing connectors I always went with T&B Snap-N-Seal. DirecTV had an "official" brand of connector but I preferred T&B universal types (red version) that would work with single or quad shield and they had internal O rings. I experimented with Stuff brand dielectric grease but decided not to adopt it for our uplink center use due to the mess and it dries out causing you to clean the crumbs out of the connector whenever you had to swap equipment out.

Two or three wraps of Scotch 33+ is fine for most of the outdoor F connections you will encounter on satellite equipment.

Spend the money on Permatex silicone dieletric compond, much better stuff. Does not dry out on a sparkk plug boot next to a 500 degree header.

 

[rmccolman]

Actually, I think I've got the Permatex stuff. Thanks.

 

[rmccolman]

After a bit of thought, I came up with a plan to keep the cable connection dry. Rather than goo-up the connection with tape, sealant, dielectric grease, etc, I've addressed the waterproofing problem a different way. Basically, I created a rain shield to place over the connector end of the LNB as well as the dish's LNB clamp. Bought a 4"x4"x4" PVC junction box, removed the cover, and cut a 1-3/4"-wide slot in one side, extending from the open end of the box to most of the way toward the closed end. I then dropped the box over the LNB and the LNB clamp -- closed end of the box facing up; open end facing down -- with the neck of the LNB inserted through the slot in the box. The LNB's feedhorn sticks through the slot. The bottom of the box extends about an inch below the bottom of the F-connector on the RG-6 cable. Any rain is deflected by the box, and dips off the box's sides, leaving the connector and connector end of the LNB completely dry. Sort of a mini rain umbrella.

If I ever need to disconnect the cable from the LNB, I can simply do so by first lifting the box off the LNB and LNB clamp. No tape to remove or goo to contend with.

Richard

 

[FTA4PA]

After a bit of thought, I came up with a plan to keep the cable connection dry. Rather than goo-up the connection with tape, sealant, dielectric grease, etc, I've addressed the waterproofing problem a different way. Basically, I created a rain shield to place over the connector end of the LNB as well as the dish's LNB clamp. Bought a 4"x4"x4" PVC junction box, removed the cover, and cut a 1-3/4"-wide slot in one side, extending from the open end of the box to most of the way toward the closed end. I then dropped the box over the LNB and the LNB clamp -- closed end of the box facing up; open end facing down -- with the neck of the LNB inserted through the slot in the box. The LNB's feedhorn sticks through the slot. The bottom of the box extends about an inch below the bottom of the F-connector on the RG-6 cable. Any rain is deflected by the box, and dips off the box's sides, leaving the connector and connector end of the LNB completely dry. Sort of a mini rain umbrella.

If I ever need to disconnect the cable from the LNB, I can simply do so by first lifting the box off the LNB and LNB clamp. No tape to remove or goo to contend with.

Richard

Pictures! Pictures!

 

[rmccolman]

Pictures! Pictures!

Images attached. I hope these help.

Richard