RG6 question

[Mike500]

Copper coated center conductor coax, known in the industry as "Copperweld" conductors, is better for most applications than solid copper cable. It maintains impedance characteristics better in real world environmenta than solid copper. Prior to copperweld, the industry used "hard drawn" copper, but found Copperweld to be more durable. "Hard Drawn" copper is no longer made for the industry, and can only found in the wired POTS (Plain Old Telephone Service) applications, because it is used for it's long distance conductivity at -50 VDC and 90VAC for telephone service in long line rural and remote drops. At higher frequencies in broadband video transmission, the outer surface of the conductor carries the signal. This is known as the "skin effect." The only advantage to solid copper is conductivity for lnb and multiswitch DisqEc switching. In that case. Monster Cable with soild copper center conductor and solid copper braid would be best. Most Coax has aluminum braid. Quad shield with more braid wires is better for low voltage conductivity than dual or regular shield.

Basically, for mechanical durability, Copperweld conductors are better at maintaining signal impedence match for signal integrity over the life of the cable. Solid copper conductor changes impedence through stretching and drawing and bending, which changes the distance between the center conductor and the outer shielding layer.

So, solid copper center conductor cable does not cost more, because of the extra copper involved. The industry has swayed away from it more and more. Since it is less available, manufactured in smaller quantity and must be special ordered in many circumstances, it cost more for the user as the result.

For DishPro. any good quality 60% plus shielded RG6 is fine. Some older budget 40% shield RG6 is problematic with DishPro. It was, however, fine for older legacy Dish and DirecTV equipment.

 

[red hazard]

Everyone has opinions. These are some of the factual specs on Belden 1694A which has a 95% coverage copper shield. If you want the best you're going to pay for it though.

Nom. Characteristic Impedance: 75 +/- 1.5 ?
Nom. Conductor DC Resistance @ 20 Deg. C: 6.4 ?/1000 ft
Nominal Outer Shield DC Resistance @ 20°C: 2.8 ?/1000 ft
Losses frequency (Mhz) vs. db/1000ft:
360 3.43
540 4.25
720 4.95
750 5.00
1000 5.89
1500 7.33
2000 8.57
2250 9.14
3000 10.67



Note the tight specs on impedance. What are the specs for for the brands/types advocated in some of the opinionated postings on this thread and what standard to they test too (assuming they even test to a standard)?
Also note the low DC resistance of the shield. What brand/type is REALLY better?

 

[Mike500]

Coax is like gasoline. Gasoline is composed of 6, 7, and 8 carbon with hydrogen molecules in a chain or other molecular configuration. The percentage of the 8 carbon molecule to the whole is the "OCTANE RATING." Using a higher octane rating in an engine that requires less is a waste of money. Contrary to advertising, higher level cable does not provide better performance in a digital dbs reception situation.

 

[Carl B]

Since you asked, stamped on the Zenith RG-6 Quad-Shielded cable:
CAROL (R) C5785 RG6 ... 18 AWG 75C SWEPT to 2.3 GHZ E60233-8 CL2--CATV--CM (UL) C (UL)--Made in USA 000018873

Which tells me this is General Cable's Carol brand C5785 coax, which has 18 Ga. Solid Copper Clad Steel w/ 2 100% Flexfoil shields and 1 60% Al braid shield, and 1 40% Al braid shield w/ a combined nominal shield DCR of 3.7 ohms/meter.

Losses frequency (Mhz) vs. db/1000ft:
200 2.83
500 4.53
1,000 6.59
1,800 8.80
2,200 10.10

Now if I'm an engineer (which I am, but mechanical, not electrical) writing a proposal spec, I spec the cheapest thing that can still do the job and/or meet the customer's performance spec in the RFP. If I'm Joe six-pack trying to make a coax run from my attic or chimney antenna to my new Dish 811 receiver, then I go with the best I can get that is readily available from nearby vendor with an outstanding return/satisfaction policy. Don't diss what works well for a given situation!

 

[Claude Greiner]

To be honest, I used to be a big believer in using only the best cable when doing installations, making sure it was sweep tested and 100% Copper.

The truth of the matter is that wether the cable is made in the good old USA, China or some 3rd world country it really doesn't make a difference in terms of performance. The Quality of the cable being made over seas has really improved over the years where I feel confortable using it in my every day installations.

However with that said, there are 3 keys to doing a good installation....

#1 Use good Quality F-connectors. I highly recommend using compression connectors. First of all they provide a quality weatherproof seal and will not easily come off the cable

#2 Use as little connections as possible. Try not to use Barrol connectors, its better just to run an entire piece of new cable. For every connection, its 1 more point where you could have a failure.

#3 Avoid sharp turns, and leave plenty of slack when making connections and do not run nect to electrical wires. This is very important to avoid interference, in addition leaving enough slack is good for Drip loops and ensures that if you need to replace the connector in the future you do not have to use a barrol connector.

One thing I will say is that if you doing any type of perminent installation such as fishing cables through walls, or a pre-wire then by all means use the best Cable Available such as 100% Copper Cable and Quad Shield.

For stuff you run along the outside of your house, then the cheap cable is fine to use since its not considered a perminent installation. Chances are in the next 7-10 years you'll be changing service providers or re-running it anyways!

 

[Mike500]

I agree with eveything Claude says, but the copper coated steel stuff is better for in wall fishes, since it is less likely to kink or stretch and change impedence characteristics. Most every install I now do is high end stuff, from homeowners who has had bad experiences with "fulfillment" installers, who got "free" installs.

Copper coated steel cable was created for strength, not as an economy measure. It was discovered that long distance aerial drops degraded with age due to fatigue stretch of the cable's weight. That's also why they came out with messenger cable. For aerial drops of up to 150 feet, Article 820 of the 2002 NEC requires a 17 ga steel messenger wire.

 

[Bones378]

If money is not an option, what would be the most/best recommended compression tool for use with Snap-N-Seal connectors? I'm looking for something that is dependable, easy to use and provides the most expandability for the different types of Snap-N-Seal connectors.

 

[red hazard]

Charter Cable in this area uses Thomas & Betts IT1000. I own one and like the build in stripper. Can't really state that it's the best as the only other compression tool I own/used is the SNSIT Sargent 3195CT which also is suitable for other connectors other that F. You might want to be specific on how you intend to use it and carefully srutinize the responses.

 

[red hazard]

Specifications

(Quote) the Zenith quad-shielded RG-6 coax available at Lowes meets or exceeds every RG-6 spec I've seen discussed on this forum. (Unqoute)
FACT: The superior 1 DB performance of 1694A yields about 26% less loss which could be useful in a rain fade scenario.

(Quote) Contrary to advertising, higher level cable does not provide better performance in a digital dbs reception situation.(Unquote)
FACT: The signal on the coax is not digital - - it's analog or what engineering purists call quasi-analog. The digital signal is at the output of the demod.

Regarding comments on copper clad vs solid copper; it's generally true proper copper claddling will not yield losses greater than solid copper due to the skinning effect but I doubt John, who started this post with a simple basic question, understands the phenomena. I can fully appreciate the the need for a professional installer to prefer the higher pulling tension rating and stiffness of copper covered steel; particulary when on the clock.

Regarding my comment on DC losses possibly causing problems with DiSEqC using copper covered steel, I did the calculations on 200ft of 1189A and determined that my concerns were unfounded. The amount of voltage drop was well above the 10.5 volt limitation.

 

[Carl B]

(Quote) the Zenith quad-shielded RG-6 coax available at Lowes meets or exceeds every RG-6 spec I've seen discussed on this forum. (Unqoute)
FACT: The superior 1 DB performance of 1694A yields about 26% less loss which could be useful in a rain fade scenario.

The quote above was taken out of context. The actual quote is: At least as stamped on the cable and printed on the package, the Zenith quad-shielded RG-6 coax available at Lowes meets or exceeds every RG-6 spec I've seen discussed on this forum. That quote preceded several folks getting into the published performance specs for various coax. Yes, the 1694A does lose about 1 db less per 1,000 feet than the Zenith quad-shield. That translates to between 0.05 and 0.1 db additional loss for the average home DTV antenna installation (50 to 100 feet of coax). I don't think this would be a visable, real-world difference.

The truth of the matter is that wether the cable is made in the good old USA, China or some 3rd world country it really doesn't make a difference in terms of performance. The Quality of the cable being made over seas has really improved over the years where I feel confortable using it in my every day installations.

Pardon me for going off topic here, but is it really worth sacrificing more U.S. jobs just to save a couple of bucks. I understand buying foreign when the quality of the U.S. product is inferior, but come on, if Made in USA meets or exceeds the performance of the off-shored product, shouldn't something else be a factor in the purchase besides a few cents a foot difference in cost?

 

[red hazard]

Wrong on 3 Counts

Nothing was taken out of context to skew what was stated in the posts on this thread. In Post #2 I stated, "Recommend Belden 1694A. It's not cheap but it is among the best for low loss and is tested up to 3000 MHz. DISHPRO (a form of DiSEqC) requires RG6 swept tested to a minimum of 2200 MHz."
The subject of loss was introduced in that post.

Subsequently you stated, "At least as stamped on the cable and printed on the package, the Zenith quad-shielded RG-6 coax available at Lowes meets or exceeds every RG-6 spec I've seen discussed on this forum. I've been pleased with its improved digital PQ performance versus the standard RG-6 sold at Home Depot." That piece of misinformation was stated without even checking to see what the salient parameters of Belden RG6 1694a were.

Secondly you stated in the Post #30 that, "Yes, the 1694A does lose about 1 db less per 1,000 feet than the Zenith quad-shield. That translates to between 0.05 and 0.1 db additional loss for the average home DTV antenna installation (50 to 100 feet of coax). I don't think this would be a visable, real-world difference." The fact of the matter is that the RF losses specified by the manufacturer are for 100 ft of cable NOT 1000 ft. See nominal attenutation at this link:
http://bwccat.belden.com/ecat/jsp/I...efined&P4=undefined&P5=undefined&P6=undefined
In view that DishPro is rated for up to 200ft, 2 db less loss is rather signficant.

Last, in the quote above, you state that, "That translates to between 0.05 and 0.1 db additional loss for the average home DTV antenna installation (50 to 100 feet of coax)." Obviously you don't know what decibels (db) means. It is a logarithmic power ratio for coveniently calculating satellite link budgets, long haul dedicated circuit losses or gains, etc. It is NOT LINEAR, it is base 10 logarithmic. You have to convert to real power before applying linear functions like multiplication of division. For example 3db loss is about double the loss while 6db loss is about 4 times the loss. Got it?

I don't intend to post anymore to this thread. The statements stand on their own value for the viewers.

 

[BarryO]

The truth of the matter is that wether the cable is made in the good old USA, China or some 3rd world country it really doesn't make a difference in terms of performance. The Quality of the cable being made over seas has really improved over the years where I feel confortable using it in my every day installations.

Actually, I've seen some very poor quality off-shore coax. Some of the RCA brand coax sold in Home Depot, marked Made in China, is particularly bad. The dielectric is not solid, and may not hold the center conductor perfecly aligned as the cable is bend. This will affect impedance and return loss.

 

[BigEd]

rg 6 supplier

Just for grins and giggles, check out your local electrical supply house. I don't mean Home Depot, but the one that sells to contractors and such.
I can get RG6 for 40 - 50 a spool and then pay 20-30 for shipping or go into the local supply house and pay 65 and walk out with it. To me that is a lot cheaper. The stuff I have been getting last go around is Genesis 5003 on a wooden spool. I was getting Coleman in the box, but rain/snow plays havoc with the cardboard. besides, I can make cute little chairs out of the old spools.