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Old 21-Jan-2011, 8:38 AM   #1
Yaguy
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Coaxial Cable

I'm familiar with the Belden, but I hear people talking about Commscope as well. I have a rooftop antenna and the cable goes down the roof, touching asphalt shingles- should I get a plenum type coaxial cable that can resist more heat than typical coaxial cable? It's mostly angled toward the north/west side of the house. It's a 50' run to the grounding block. Will good RG6 do? Or should I look at RG11?

Finally. What specific cable with it's designations, materials, or shieldings, braids should I try to obtain? Rather than go with what with the hardware or electronics store has from China, I wanted to buy from a local cable distributor and get some high quality coax and have them crimp on good connectors. I've read that white cable is better- heat, UV resistance etc.

Currently, I've been using- for about 18 years- Belden DUOBOND II for CATV. Yes, I believe it's RG59; but the run isn't that long after it enters the house.

Thanks.
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Old 21-Jan-2011, 6:17 PM   #2
GroundUrMast
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Belden and Comscope are two very reputable brands.

Plenum rated cable would be used when the cable is to be run through an air duct, such as a cold air return... the insulation is supposed to produce less toxic smoke if it is involved in a fire. I would not assume the plenum rating to mean that the cable is weather resistant or electrically superior in some way.

Over the years, I have used more Belden product than any other. I have only experienced problems with coax purchased through Radio Shack (However, their treatment of me as a retail customer has been acceptable, enough that on occasion, I'll still shop there). For personal use over the last few years, I have purchased RG-6 and/or RG-6/U from my local big box home improvement center, with no regrets or problems. I do not use quad shielded cable because it's harder to work with, more expensive and yields no measurable benefit. By far and away, the more significant factor in the reception of a stable OTA DTV signals has been my choice of antennas and their mounting sites.

My commercial experience is in the telecommunications industry, providing local and long-line broadcast quality audio and video transport services. In my experience, every cable rated for UV exposure was black in color, not every black cable was UV resistant. I'm simply saying that when you need UV resistance or some other specific rating, specify the requirement and be ready to pay appropriately.
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Last edited by GroundUrMast; 21-Jan-2011 at 6:33 PM.
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Old 21-Jan-2011, 7:18 PM   #3
Yaguy
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Coaxial Cable

Thanks for the great info, GroundUrMast.

I think that's the best thing... specify where I'm going to use the coax, what I'm using it for (OTA TV), and state that I'd like UV resistance, whether it be black or white.

I saw somewhere a spray called "Stuf" that you spray inside the coax connections before you connect them and it's supposed to help keep out moisture. I know that keeping all the connections moisture-free is very important as well, and had read somewhere about people even using roofing tar for that. That "Stuf" was supposed to also be used with coax seal or cold shrink tape for outer protection. - When I installed the antenna, 18 years back, I had only used regular, black electrical tape under the weather boot on the F-connector on the balun, and on the connections on the grounding block outside.

But do you think switching a 50' outdoor run from Belden Duobond II RG59 to good RG6 will be noticeable in UHF picture quality?

Thanks.
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Old 21-Jan-2011, 7:45 PM   #4
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As far as sealing is concerned, common electrical tape is less than ideal. When water leaks in (and it will) the tape holds the moisture there. Coax seal tape is far more reliable: Example or 3M Scotch 2228. Use of the older crimp connectors has been made obsolete by the newer, superior design compression connectors, some of which are rated as water tight: Paladin-Waterproof-Compression-connectors

A few folks use dielectric grease: http://www.amazon.com/Permatex-22058.../ref=pd_cp_e_1 Though others have reported some signal loss. I have not seen that happen and have had experience with dielectric grease in applications on microwave systems mounted 130 feet up communication towers. I have seen dielectric grease attack some types of weather boots (from Radio Shack) I don't know if the boot was natural rubber or a synthetic material.

RG-6 will have less loss, but that alone would be impossible to observe on the screen in most situations. If there is water in the coax now, I would expect improvement if you replace the cable with new. Water will change the electrical properties of any coax, in unpredictable but most certainly, negative ways. For analog signals, 'snow' and 'ghosting' would be common symptoms of bad coax, but those symptoms can be caused by many other factors as well.

Eighteen years is enough reason to consider replacing the coax, you got your money's worth out of it.
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Last edited by GroundUrMast; 7-Nov-2011 at 4:15 AM.
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Old 22-Jan-2011, 8:10 AM   #5
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Thanks again, GroundUrMast

Strange thing with the old RG59 cable, UHF 32 has never been as crystal clear- seems to have gotten better with age, whereas VHF 6 has degraded, as has VHF 10 some. VHF 2 is perfect. Good idea to seal up the connections from new. Thanks for the links.
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Old 6-Nov-2011, 11:20 PM   #6
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Thanks

Maybe that is the missing link on my signal. I changed the cable down (75 feet) from the preamp, new connectors etc. but did not change the cable from the preamp to the antenna. Will check that next time I drop the antenna tower.
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Old 26-Dec-2011, 7:39 PM   #7
slowhike
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In this thread http://forum.tvfool.com/showthread.php?t=2895
you guys have helped me narrow down my antenna choice to the Winegard HD-8800 http://www.winegarddirect.com/cview....nly%20Antennas, which I just ordered from Winegard.

I did not order the coax cable from them because the only ready to use length they offered was 100' & I will need far less. From antenna to TV will be less than 25', but I plan to buy a 50' length & have a little room for testing different antenna locations, etc.

As start looking at were to buy the cable (either local or on line) I think I need help with a few more questions in order to get the right stuff the first time.

I have read advice from GroundURMast in this thread, but to be sure I get it right....
1)....Are the "F connectors" what I need for both the antenna I ordered & the TV?
2)... looks like I need to order the sealant tape for were the cable connects to the roof top antenna, right?
3)... from GroundURMast advice, I see I don't need to worry with (or pay extra for) a supper shielded cable.
Do you have a link handy were I can order a quality 50' cable with the right type ends & the sealant tape?

It looks like I can get the tape at Lowes Home Improvement but they aren't listing the coax cable.
If you have a link & just say "This the 50' coax cable you need", I'll be happy
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Old 26-Dec-2011, 10:04 PM   #8
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Here is an example of a 50', factory assembled piece of RG-6 dual shield. Very reasonably price at just over $9 US.

http://www.amazon.com/Patch-Cable-Pr.../ref=pd_cp_e_3

Home Depot typically stocks similar product: http://www.homedepot.com/webapp/wcs/...cStoreNum=4706

@ slowhike, 1) Yes, F connectors on both ends. 2) Yes, sealing tape protected from UV with a couple of wraps of black vinyl electrical tape.

Amazon also can source coax seal tape: http://www.amazon.com/s/ref=nb_sb_ss...refix=coax+sea
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Last edited by GroundUrMast; 27-Dec-2011 at 1:18 AM.
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Old 27-Dec-2011, 12:55 AM   #9
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Thank you sir. Both items ordered.
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