Wiring question

[Roadwarrior]

Wow. Well, you've really opened my eyes. Thanks for that.


But, if it's all the same to you, I'll keep doing what I'm doing and conform to Dish Networks standards.

 

[Andrewwski]

I'm not telling you not to meet Dish standards. I hope you do. You don't create the rules, but you have to follow them. I understand that and you're doing nothing wrong.

All I'm saying is that there's no reason RG59 won't work in those scenarios. Funny how each member gives a different reason why it won't work too.

 

[Roadwarrior]

Other, not so tech savvy customers could read this and get ideas. Customers argue with me enough on installs when I tell them things they don't want to hear(No the dish can't go in the attic ma'am. No I can't mount the dish on the telephone pole across the street, sir.). Yeah, if you got 15-20 foot of 59 in the line, it could very well work. And has, for me, a few times. Despite Dishes standards, I would feel much more comfortable using the good stuff, since I am responsible for that job, for at least the next 90 days.

I guess what I'm trying to say is, don't give people any ideas. RG-6 is better all around, I long for the day when it(RG-59) is nothing more than a distant memory, and won't be found in any house, anywhere in the states. Of course at that point the standards will have changed again....


eh

 

[Andrewwski]

I agree with you there. You definitely don't want a customer to want 100 feet of RG59 in the line.

I've seen all sorts of whacked up things in rural areas. A ton of them on telephone poles, but from what I can find out the poles are the property of the landowner (they have the poles put in themselves, electric co. just puts up the meter). What's worse is trees though. Who in their right mind mounts to a tree?

Those have to be the not-so-tech savvy customers installing them theirselves.

 

[Furbox]

I'm not saying to not follow the standards a company has set, I'm just saying the cable won't burn out, and yes this whole discussion has been about cable burning out, not about causing damage to other parts of the system, which I find hard to believe also. Unless there is a defect in the cable or a passive device in the line, I've never seen a piece of cable burn out anything.

 

[Tyralak]

Well as someone who has been in the TV repair, antenna and satellite installation and rf distribution business since 1974(33 years), I can honestly say I have NEVER seen an RG59 cable 'burn out' due to exceeding it's specs under normal conditions. Of course lightning doesn't count in this discussion. DSS and Dishnet receivers are very limited in the amount of current they can put out. I have never seen any working LNB setup that draws more than 1000 milliamps. Even if the LNB shorts which could theoretically cause infinite current to flow, most receivers are not capable of putting out much more than 500 milliamps. All DSS and Dish receivers put out 18 volts and 13 volts depending on polarity. BUDs use 21 volts for LNB power.
Exceeding it's tested frequency will definitely not damage or wear out a cable. The cable will only pass what it can. You cannot 'force' it to pass anymore(at least not with the ammount of rf power coming out of an LNB).

According to Echostar's engineering department, (I asked specifically last week) the dielectric (what is actually carrying the signal) in RG-59 breaks down when used in DPP installations. DPP receivers actually put out 750 milliamps not 500. And since DPP by it's very nature isn't voltage switched, it's putting out 19.2 volts constantly not switching between 13 and 18.
In 90 percent of the cases when I come out to fix a DPP system which was installed on RG-59, and find the cable to be bad, the cable not only doesn't pass a signal, it won't even tone out anymore. This isn't due to just "30 year old cable" as the other poster put it. This happens on NEW RG-59. The reason Dish stopped including the little piece of RG-59 in the box with receivers (the one that says only for use between receiver and TV) is because we had so many trouble calls where the original installer was too lazy to make another jumper, and used it between the receiver and wall plate. I've replaced more of those than I can count. It's the same reason we have to replace wall plates that contain low frequency barrel connectors. The cease to function after a period of time, often a very short period of time. Low frequency barrels are a big trouble call driver. I go to at least a couple a week where the installer left a low frequency barrel in the system, and it stopped working.
When the DPP stuff first came out, I was still a subcontractor, and I didn't believe it either. I always said "That's a bunch of crap. It worked fine when I was there." That is until I started getting chargebacks when the company I worked for extended the chargeback time from 3 months to 6 months. I started finding out that 59 really doesn't work that well. I had to go back to those jobs where the 59 "worked fine" and replace it. Apparently this had been happening on regular DP also, but back when the chargeback time was only 3 months, I never noticed it.
Look, I might buy the previous argument that it had to be all manner of external factors, (connectors, staples, etc) and not the 59, except for the fact that I've never seen RG-6 fail like that. The only times I've seen RG-6 fail is when there was significant damage to the cable. 59 fails when it's in perfectly good shape.

 

[Andrewwski]

According to Echostar's engineering department, (I asked specifically last week) the dielectric (what is actually carrying the signal)

Dude, you lose absolutely any credibility you had right there.

The dielectric is the insulative material between the conductor and shielding.

And no, it can't break down. Furbox is right. Under your theory, RG6 will also break down, just at a slower rate, but eventually failing too.

 

[Tyralak]

Dude, you lose absolutely any credibility you had right there.

The dielectric is the insulative material between the conductor and shielding.

And no, it can't break down. Furbox is right. Under your theory, RG6 will also break down, just at a slower rate, but eventually failing too.

Perhaps I wasn't as clear with what I wrote as I should have been. I'm right now looking at some of the DNS training materials. The diagram shows the signal as a wave bouncing from the center conductor to the braid through the dialectric, which is why sharp bends or pinches in the cable cause signal loss. The dialectric is indeed an insulator, but that isn't it's only function.
I submitted this question to the QAS (Quality Assurance Specialist. Our quality inspector) He said this is the answer from engineering. So, that's what I got.

I noticed you didn't touch the rest of my post. Look, either you're right and RG-59 works just fine for DPP, and the rest of us who deal with this stuff every day are imagining all these failures, or you're wrong.

RG-6 is rated for those frequencies, so no it won't.

 

[Andrewwski]

Sort of. The center conductor is what is carrying the signal. The dielectric is irrelevant - you just need to know that it's there. It doesn't matter if it's plastic or foam or whatever, just understand that it's an insulator, and it's physically separating the shielding from the center conductor.

The center conductor is what you transfer the signal through. But if it were just the center conductor, without any shielding, you'd basically have one really long antenna. You would be losing signal through it, as well as gaining interference.

That's where the shielding comes in. It separates the outside environment from that of the center conductor. Therefore, the signals traveling through the center conductor are broadcast off into the dielectric, where they hit the shielding, but cannot escape. If the shielding was not present, they'd be broadcast into the surrounding environment. The shielding also acts as an interference barrier. Any signal outside the cable will hit the shielding and not pass through, therefore not impacting the signal.

The dielectric only has relevance in the fact that it's there. It doesn't matter what material it is made from, as long as its not conductive. So there is no possible way that the dielectric can break down. Unless, of course, you propose that somehow the dielectric suddenly gains a degree of conductivity, therefore shorting together the center conductor and shielding to some extent.

I'm not saying that RG59 is "just fine" for DPP. I have tried to make it clear that it is not ideal, and should not be used when avoidable.

However, the issues with RG59 and DPP are not this magical "burn-out". It has to do with signal attenuation of upper frequencies, which are used more in DPP than DP and Legacy. Typical RG59 attenuates 3000 mhz at about -17 db per 100 feet, while typical RG6 attenuates 3000 mhz at about -10 db per 100 feet. THAT ALONE is the issue with DPP and RG59. Over a long cable run...which can be the typical length from the distribution point to a room, the higher frequencies are attenuated too much and do not pass well.

There is no such thing as "burn out." Explain to me, in molecular terms, what happens when you try and pass higher freqencies through a cable that cannot pass them. Nothing. Absolutely nothing. They just don't pass. The cable doesn't heat up. Nor does some slow chemical reaction take place that degrades the conductivity of the copper or the insulation of the dielectric. Not happening.

Which is why your theory applies to RG6 too...if the cable is really being degraded, and RG6 is the same exact thing but with a thicker conductor, thicker dielectric, and more shielding, the same process will take place, just at a slower rate.

 

[KKlare]

To some extent the coax cable is a wave guide. RG-6 has two advantages.
(1) The foam dielectric attenuates the high frequency signal less between the core and shield than the solid polyethene of RG-59.
(2) The center conductor is larger in diameter to compensate for the lower dielectric constant of the foam and to maintain the 75 ohm impedance. As a benefit, the larger core lowers the resistance at low frequency--power and switching--which is where it could "burn out."
(Aside: the lower dielectric constant allows faster propagation, say .8 vs .6 speed of light (c), IIRC. Ideal coax would have only vacuum, air, or nitrogen dielectric with near 1.0 c and little dissipation loss. Minimal foam support is expensive and very inflexible, say $5 per foot and 2' radius of turn, if corrugated.)
RG-6 is a good, inexpensive compromise. RG-11 would be better, larger for DC but still would have solid poly and its dissipation and a tinned stranded core--twice the diameter and say 4 times the cost.
-Ken

 

[Tyralak]

To some extent the coax cable is a wave guide. RG-6 has two advantages.
(1) The foam dielectric attenuates the high frequency signal less between the core and shield than the solid polyethene of RG-59.
(2) The center conductor is larger in diameter to compensate for the lower dielectric constant of the foam and to maintain the 75 ohm impedance. As a benefit, the larger core lowers the resistance at low frequency--power and switching--which is where it could "burn out."
(Aside: the lower dielectric constant allows faster propagation, say .8 vs .6 speed of light (c), IIRC. Ideal coax would have only vacuum, air, or nitrogen dielectric with near 1.0 c and little dissipation loss. Minimal foam support is expensive and very inflexible, say $5 per foot and 2' radius of turn, if corrugated.)
RG-6 is a good, inexpensive compromise. RG-11 would be better, larger for DC but still would have solid poly and its dissipation and a tinned stranded core--twice the diameter and say 4 times the cost.
-Ken

Thanks for the great info!