OTA Cabling: RG-6, RG-59, RG-11, Twin-Lead, Crimping, Other Tips

[Jase88]

prodigy28, a coax-powered preamp won't power up if the outside of the connector fails to make good contact with the coax braid. Without power, the pre-amp passes very little signal--effectively becoming a strong signal attenuator.

Make sure that you're using the proper connectors for the cable size, and that you're preparing the cable with a proper prep tool for that cable size.

For example, you cannot use an RG-59 connector on RG-6. Connectors normally fit snug, but if you cannot get it to fit properly even when forcing it, chances are there is a connector and cable size mismatch.

[roger1818]

cayemar, I second what Jase88 said.

One other thing to consider; you say it "is connected to a splitter to supply the signal to the cable TV dimples in various rooms in the house." Optimally you should only connect the coax lines that are actually connected to a TV/Tuner using a splitter that is the right size for the number of splits needed. The signal power will be equally split among all ports of a splitter whether it is connected or not so using the right sized splitter will reduce the amount of signal loss. If you must have unused ports, make sure 75ohm terminators are connected to them.

[roger1818]

prodigy28, the other thing to check when terminating your own coax cables is that a strand of braid isn't shorted to the centre conductor. This is a common problem as it can happen very easily, no matter how careful you are. The best way to test is is with the cable not connected at either end, measure the resistance between the shield and the centre conductor and make sure it is infinite (open).

[prodigy28]

Jase88, thank you for the help.

That is another mistake I made by cutting away the braid. After more reading I understand the Quad RG6 has a layer of braid, foil, then another layer of braid. To make the connection best, should I remove the layer of foil and push both layers of braid back over the cable before pushing the connector on?

I want to be 100% certain before I climb back on that roof. I had it installed for me but went up myself to attach the CM7778. Most horrifying experience of my life. I hate heights and my roof is very steep. Yes, I am a wuss

Thanks again.

[prodigy28]

Thanks for the information roger1818. I have no idea how to measure the resistance between the shield and centre conductor. Hopefully google will help

[roger1818]

Optimally you would use a multimeter, but even a continuity tester should work.

[cayemar]

Thanks for the help guys. Knowing that this is doable will make this much easier both installation and "keeping the wife happy" wise.

I will have to read a bit more to get an idea of how much signal loss we are talking about and the best way to amplify the signal once I get hold of it.

[Francey]

Hi all. New member here.

Question:
I am setting up an air antenna .. (towers 20 miles at most distance away)
I am using the existing former Cable Co. access to the tv in the house.

A. The incoming Cable coax goes to a splitter with 3 outlets. 2 outlets are marked 7dB and one 3.5dB. They are wired to 3 different t.v.areas of the house. (L.R., D.R. B.r.)

1. What is the meaning of the 3.5dB vs the 7dB's shown on the Splitter?

2. I intend to disengage the splitter entirely and connect the antenna coax directly to the L.R. Cable Co. coax cable? I will ONLY be using this one TV. Is this OK?

3. I was planning on using basic R6 coax because the existing Cable Co coax to the L.R. tv is 25 yrs old and I can't discern what size cable the Cable Co. has used. Is that OK?

4. Since the Cable Co has all the installed grounding, I don't need to worry about grounding anything. Is that correct?

5. Who owns the Cable Co box attached to the house.. me or them?

Thanks in advance for any advice you may offer. Do keep in mind I'm in a learning position, not experienced, so word your replies so I can understand what you are telling me. Thank you. Francey

[JamesK]

A 2 way splitter will have just over 3 dB loss per leg, due to the power being split between the 2 legs. If split 4 way, it'd be 6 dB. So, in your splitter, you've got one splitter feeding another. They also call it 3.5 & 7 to allow for additional losses in the splitter.

[roger1818]

Originally Posted by Francey

I am setting up an air antenna .. (towers 20 miles at most distance away)
I am using the existing former Cable Co. access to the tv in the house.

A. The incoming Cable coax goes to a splitter with 3 outlets. 2 outlets are marked 7dB and one 3.5dB. They are wired to 3 different t.v.areas of the house. (L.R., D.R. B.r.)

1. What is the meaning of the 3.5dB vs the 7dB's shown on the Splitter?

As JamesK said, it is the amount of signal loss on each port. This type of 3 way splitter is known as an unbalanced splitter as not all ports have the same amount of loss. You can also get balanced 3-way splitters that have equal loss on all ports (about 5.5 or 6 dB).

2. I intend to disengage the splitter entirely and connect the antenna coax directly to the L.R. Cable Co. coax cable? I will ONLY be using this one TV. Is this OK?

Yes, using a straight coupler is the best thing to do if you are only planning on connecting one TV. You should never have unconnected ports on a splitter.

3. I was planning on using basic R6 coax because the existing Cable Co coax to the L.R. tv is 25 yrs old and I can't discern what size cable the Cable Co. has used. Is that OK?

For most people, RG-6 cable is optimal. Quad shield is only necessary in very noisy environments and RG-11 is difficult to work with.

4. Since the Cable Co has all the installed grounding, I don't need to worry about grounding anything. Is that correct?

Incorrect! You will need to ground your antenna mast. Also, don't assume the cable company properly grounded their cable. Besides, if they did, it is likely outside the house in a locked box.

5. Who owns the Cable Co box attached to the house.. me or them?

Typically they own the box and you own the cables inside your house. This can vary from jurisdiction to jurisdiction though.

[Archerotor]

Got some Remee RG 6, made in USA. The writeup lists: Broadcast Coaxial 75 Ohm RG 6U Cable. 18 awg solid bare copperweld. Cellular Polyethylene dielectric, Coaxial shielding tape, bonded (100% coverage), Braid shield, Polyvinyl Chloride jacket. Used for video display, point-of-sale terminals, Local Area Network controls and CATV broadcast applications swept to 3.0 GHz. Temperature Rating: -20°C to +60°C Minimum Bending Radius: 3.50 in. NEC Article 725 & 820, UL Subject 13 & 1581, Types CL2/CATV Spool. BLACK.
** Compared to better known coax would this still do a good enough job for OTA? - My old Belden RG 59 had a temperature rating of -40°C to +80°C. The roof might get hotter than 60°C; yet it is mostly on the northwest side.
Ideas?

[Jase88]

Even with a black roof, I'd believe that 60c at the surface would be a rare event in Vancouver, BC. If it's a concern, then certainly shop around for a better cable spec.

[ota_canuck]

Apparently roof materials and colour matters:

http://www.giss.nasa.gov/research/news/20120307/
The dark, sunlight-absorbing surfaces of some New York City roofs reached 170°F [77°C]on July 22, 2011, a day that set a city record for electricity usage during the peak of a heat wave. But in the largest discrepancy of that day, a white roofing material was measured at about 42° cooler.

I'm not sure how high BC temps get or how long they can hold those high temps throughout the BC peak summer period.

60C = 140F, therefore direct contact with hot black shingles and flashing material could become a long term breakdown of the cable materials.

There are several listed here: Which one do you have?
http://www.remee.com/technical-assis...uct-specs.html

[Archerotor]

My coaxial cable reads: Remee 3122598 RG6/U TYPE CMR 18AWG C(ETL)US. OR CATVR SWEPT TO 3.0 GHZ ...

The roof thing got me remembering about what I saw on a weather/climate website here:
http://wattsupwiththat.com/2009/03/0...-the-infrared/

The roofing materials greatly affect the amount of heat that will be abosorbed and then reradiated. I have grey fibreglass type shingles by Cambridge. They still can get hot. And despite what people say, we can get a few 30°C+ (86°F+) air temperatures here in the Vancouver area, over the Summer.

http://www.climate.weatheroffice.gc....Month=8&Day=01

Now... if I had an Infrared camera.

[PrinceLH]

Probably the wrong place to send this question, but I might get an answer: What would you recommend for cable, when installing a C Band satellite dish? RG11? RG6? Not sure what to use. Planning to set up a 6' dish and re-activate my DSR921.