Continuity problem with coax

[Silverback98042]

The coax cable has a continuity problem somewhere between the connection on the side of the trailer, and the end that is to connect inside. We have had intermittent issues when trying to connect to campground provided cable tv, but can't make a connection now that we're connecting to Dish satellite. Running coax directly to the receiver from the dish works great. The problem is with the internal coax in the trailer.
I guess it's necessary to replace that coax, but don't know how to go about that.
Any ideas?

[BruceMc]

Here's why mine wouldn't work if I had tried the park cable:



Yep, straight from the factory.

I found this as I was disassembling the overhead TV cabinet on our 2016 Sunseeker. We didn't want the overhead TV, rather, we'd have an overhead bed with a swing-out TV on the sidewall. But for 15K off, and it being the only Chevy on the lot, we decided we could do a lot of mods for that much money. It has been a pleasure not having the 32" TV and console up there, though I miss the storage space. That'll be fixed when I re-build the cabinet on the right hand wall in the overhead.

[CA_Traveler]

Install a new coax from the satellite receiver to the nearest outside compartment. There is no compelling reason to run the coax to the left back corner of the rig.

[D_E_Bishop]

Tom, Once again I said RG8 and meant RG6. I can explain why this happens to me but you really don't care about my learning disorders. As I said in my second post, I don't know much about coaxial cables and their characteristics and so much has happened in the electrical/electronics fields since I was active and employed in them and I don't really care to keep up to date but I did want to check out this difference.

I can say I have never used or tried to use RG8 in any installation nor have I ever purchased any for any purpose.

I still believe that in general the way that RV manufacturers install these cables "sucks". My Bounder was a nightmare and I finally abandoned all of the old RG59 cables and pulled in new high grade RG59. This was also before HD and RG6 was even mentioned in any stuff I read about RVs. I also pulled in a good quality HDMI cable so we could play the same DVD on both sets by using a HDMI splitter.
If I remember correctly he can rum a HDMI cable from his satellite box to his TV(I'm assuming he has a HD flat panel TV) and leave his Cable - Antenna wiring(RG59) alone and continue to use it for all other TV signals.

It seems to me that the OP is saying when he tries to hook the cable for his satellite dish to his house wiring that it doesn't work. My suggestion about running all new cable (with the exception that in my dyslexic state I put RG8 instead of RG6) is the best solution for him.

When I suggested 300GHz Compression fittings I was only advocating what I had learned from the Techs at Orvac's Electronics Supply.

I would also recommend F81 Female-Female connectors if needed. The ones that have the Blue insulator is higher quality than the ones with the milky white or white insulators.

Okay if I'm wrong again, let me know.

[SCVJeff]

fpresto is correct on his analysis of coax, although the RG-59 used in MOST installs is about the worst junk around. Copper coated steel wire, ultra soft dielectric that allows the center wire to move around and cause ALL KINDS of issues so strange you would likely never put your finger on whats going on Google "Periodicity"). And a shield you can drive a truck through. As he says, if you know what to look for, in these short runs, the differences in loss can be hardly noticeable.

BUT.. if doing a clean run, buy GOOD RG-6 anyway and you're that much further ahead.

[Silverback98042]

I don't even pretend to have a strong grasp on this type of thing, so I'm at the mercy of the information I get from others. I have seen a Utube video that states that the coax installed in RVs is not adequate for satellite reception. As suggested earlier, I thought pulling the small wire out a little more might help, but the receiver/dish can't make a connection. I'm resigned to the fact that I'm going to need to install another coax lead into the trailer.
I thank everyone for the input and suggestions.

[cgmartine]

Silverback, have you positively identified the problem as a continuity issue? Home Depot sells a Klein Explorer Coax tester for ten something dollars. Before going to all the trouble and expense of replacing the coax cable, I would invest in the tester.

[wa8yxm]

fpresto wrote:
Myth 2 - You must use RG-6 because of the increased loss in RG-59. With both being of good quality on runs of over 100ft that might have a slight effect but in typical RV run you would see no difference. It is not uncommon in our testing to have a good quality RG-59 outperform many RG-6 cables.

Somewhere (in the cabinet in the back bathroom and over the window in the front Half Bath both) I have some charts, Courtesy of Belkin Cable.

What they show is that both RG-59 and RG-6 come in lots of different qualities.. The Best 59 actually does outperform the cheap 6.. But the best Six.. Well... on the average RG-6 has about 1/4 the loss of 59. So it will perform better No matter the frequency.

The difference however is that at lower (VHF) even mid range (UHF) the difference may not be worth notice.. At Sat.. It means that 100 feet is like 400 feet and you have a 300 foot limit.

But if you get QUALITY cable.. Well, that makes an even bigger difference in both types.

[Silverback98042]

I have two connection places on the side of the trailer, one is labeled DSS, the other is unlabeled. I assume DSS is the one I should be addressing, though I don't know what DSS stands for. At one time, I was considering pulling a new coax cable through the trailer, using the existing route, but is it possible there's some kind of splitter box involved? That would make that impossible, at least for me. My first order of business is to verify that the connection inside the trailer is good, by pulling out the wire slightly, and confirming that the threaded connector is seated properly. If that doesn't solve the problem, I'll have to consider installing another connection though the wall, but that's a little intimidating. I'll keep you posted.

[Silverback98042]

Thanks for all the responses! You've given me a lot to consider. I'm going to take a systematic approach and work through this.

Thanks to all for your input and ideas.

[fpresto]

Let me preface my comments by saying I use a good RG-6 in all of my installs at home or in my RV; but every time this subject come up there is a lot of myths that come up and are repeated over and over. I work with all kinds of cabling in a test lab from cheap to some that are hundreds of dollars per foot.
Myth 1- Rg6 is inherently better than RG-59. That is impossible. There is no standard for either. RG is an old military term from the 50s. It means Radio Grade. It has long been replaced by Mil-Specs. I could take any cable, stamp RG-6 on it and legally sell it.
Myth 2 - You must use RG-6 because of the increased loss in RG-59. With both being of good quality on runs of over 100ft that might have a slight effect but in typical RV run you would see no difference. It is not uncommon in our testing to have a good quality RG-59 outperform many RG-6 cables.
What makes a good cable? First is the center conductor. Is it copper or just copper coated steel? Second is the insulation. Is it single, double or quad? Third is the outer sheath material. Will it hold up to movement, vibration, UV rays, etc. Last, but often overlooked, is the end connectors. Are they sealed against weather? Is the exposed center conductor the right length?
With all of that being said, in a typical use, a decent medium grade cable will work fine just don't buy a cheap imported cable just because it has RG-6 stamped on it to try and save money.

[Tom_M1]

D.E.Bishop wrote:
I'm not a expert on cables but isn't the difference between RG6 and RG8 in the shielding and core conductor.

The main difference is the impedance of the coax, RG6 is 75 ohms and RG8 is 50 ohms. RG8 is also larger in diameter. The impedance must match the impedance of the devices being connected. RG8 is used a lot in communication equipment such as 2-way radio, ham and CB. Most TV stuff is 75 ohms. TV antennas for RVs are usually 75 ohms. The typical home TV antenna is 300 ohms and requires a matching transformer (balun) to connect to coax.

[SCVJeff]

And if you run one, run two...

[D_E_Bishop]

Tom you are absolutely correct. T comment about when they hook up to satellite fooled me. And yes I meant RG6., which is to the best of my knowledge 75 ohm characterization. And in my opinion, my answer is among the best way to deal with a bad cable.

I had so many pieces of cable from my antenna to the B.O.M.B.s in my old rig that I couldn't pull out that I just ran a new piece from the antenna head to the B.O.M.B. The Winegard batwing pcb on the Winnie was so corroded that I had to replace the head and cut off some of the cable and put new fittings everywhere. I needed about 6" more from the power supply and gave it a little tug and it moved really easy. I guess they rand them in a groove in the roof insulation.

I have read Chris' article but sometimes the answer is not a tune up but replacement. If the equipment is okay it's easy. And he also refers to RG6 in that article. I'm not a expert on cables but isn't the difference between RG6 and RG8 in the shielding and core conductor.

Also trouble shooting coax in a motor home is a real pain for most owners.

[Tom_M1]

D.E.Bishop wrote:
To answer your question and not trouble shoot the problem, go to a true electronics store, either a S&B store or an online store and buy enough RG8 coax cable to go from what ever point you wish to use to your Sat. box, a package of F-Type, RG8 compression connectors(3GHz is what I am using), an installation tool, a cable stripping tool and a external cable connector plate.

I assume you mean RG6. RG8 is 50 ohm and not meant for TV which is 75 ohm.

I believe that the OP is not having problems with satellite but with his cable TV feed.

Here's a link to an article by Chris Bryant on TV issues:

Tune up your TV antenna

Although it's about antenna tune up it also addresses cable repairs