DTV installer will not use existing RG59 runs

[Bob Nielsen]

Hey gang, there are many flavors of both RG-6 and RG-59 (back when these were mil specs, it wasn't as confusing), so the generalizations don't hold. You can find RG-59 spec'd at 10.9 dB/100ft at 2000 MHz (RG-6 is around 9 dB/100 ft at that frequency). The DC resistance will be higher, as well. With good foil and braid outer conductors, a solid copper center conductor and proper terminations, it can work fine for short lengths. Some older RG-59 only has a single copper braid and no foil so it will leak like a sieve at microwave frequencies (you probably can't find any RG-6 built this way). RG-6 is the right cable to specify, but 59 isn't always bad, and may be acceptable where there isn't an easy alternative.

FWIW, I have worked with coax for over 50 years, much of which was at frequencies much higher than those used here.

 

[Tyralak]

Hey gang, there are many flavors of both RG-6 and RG-59 (back when these were mil specs, it wasn't as confusing), so the generalizations don't hold. You can find RG-59 spec'd at 10.9 dB/100ft at 2000 MHz (RG-6 is around 9 dB/100 ft at that frequency). The DC resistance will be higher, as well. With good foil and braid outer conductors, a solid copper center conductor and proper terminations, it can work fine for short lengths. Some older RG-59 only has a single copper braid and no foil so it will leak like a sieve at microwave frequencies (you probably can't find any RG-6 built this way). RG-6 is the right cable to specify, but 59 isn't always bad, and may be acceptable where there isn't an easy alternative.

FWIW, I have worked with coax for over 50 years, much of which was at frequencies much higher than those used here.

I don't doubt it. However, most of the 59 pre-wire in houses is not suitable in any way shape or form. It's not the really good stuff you're talking about.

 

[Bob Nielsen]

I'm surprised that anyone would have had a RG59 installation in 1997 (see initial post). When I first got cable in 1981 (it was just being rolled out where I lived), I called the cable company and asked what cable I should use, since I was remodeling at the time. They said to drop by and they gave me about 150 feet of RG6, far more than what I needed. I was able to conceal the wiring and it saved the installer a fair amount of time when he came out after they had run their cable into my neighborhood.

 

[Donnernv]

Let's get some facts here. We are talking about digital signals, not analog. It's either strong enough or it's not. If it's strong enough, over RG-59 or RG-6 or a coat hanger, it will work fine. If it's not strong enough, it won't. It doesn't deteriorate like analog, the 1's and 0's are there, or they aren't. RG-59 has more attenuation than RG-6, so the possibility that it doesn't have enough poop over a long run of RG-59 is greater than over RG-6. But it either has enough poop, or it doesn't, regardless of the cable.

The fear about sending 13vdc and 18vdc voltage over RG-59 is groundless. In another's words from another site:
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Original Comment:
Originally Posted by stampeder
That Ian Masters fellow should be careful what he says. Again we're back to people confusing picture quality with the fact that the LNBs on the satellite dish are driven by power injected at the receiver (I think its between 13VDC and 18VDC isn't it?) so in effect both the signal AND the power are being attenuated at an alarming rate with longer runs of RG-59.

Response:
Generally I lurk and just ignore those who post incorrect information as truth but I cannot pass this thread by.

For your reference:

(typical values picked from references off the internet)
Centre conductor on RG59 = 22 gauge = 1.61 ohms/100ft
Centre conductor on RG6 = 18 gauge = .638 ohms/100ft

typical worst case maximum LNB current = 200mA which at 13V gives an effective load resistance of 65 ohms.

Therefore the difference in voltage drop between an RG59 and RG6 cable is NEGLIGIBLE (I'll leave you to do the simple math).

Original Comment:
Absolutely, the copper core of RG6 is substantially thicker than RG59 and therefore does not suffer the crippling attenuation (line loss) of RG59 that can be very taxing on the DC power injector circuitry that powers the LNB over all that cable. Its like trying to run xmas lights, a hair dryer, and a boom box through one little 2-prong extension cord. It'll work... at first. At least you can reset the fuse, but with a blown BEV box its not so easy to fix...

Response:
This implies that increasing the resistance of the wire increases the load on the receiver LNB power supply...... which is nonsense.

The only real effect of using RG-59 vs RG-6 is the attenuation of the cable at the RF frequencies (950 to 2150MHz) of interest. RG-59 is certainly worse but if his system is working as it stands without pixellation and signal drop out then he is good to go and doesn't need to worry about ripping his walls out.

(Copied from another site).
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So, this fear is groundless. And, the notion that somehow RG-59 (or any other cable) will deteriorate over time is bizarre. I don't know who could have such a notion. Cables deteriorate from weather, corrosion or maltreatment. They do not deteriorate from signals or low voltage being sent over them.

Installer guys...I don't question what you've been told or your textbook beliefs. But dogma doesn't make truth. My experience makes clear to me that RG-59 works fine if it works. Of course, RG-6 is better/preferred. But in those cases where rewiring a house is involved, try the existing RG-59.

And for what it's worth, I am a graduate electrical engineer.

 

[iwc5893]

And for what it's worth, I am a graduate electrical engineer.

In theory, you're correct. In real world experience, RG-59 fails more than RG-6. You can believe your textbooks, but I'll believe my experience.

 

[Jhon69]

Well I believe considering what the OP posted that there was no excuse to not install RG6.

 

[Mr Tony]

Installer guys...I don't question what you've been told or your textbook beliefs. But dogma doesn't make truth. My experience makes clear to me that RG-59 works fine if it works. Of course, RG-6 is better/preferred. But in those cases where rewiring a house is involved, try the existing RG-59.

And for what it's worth, I am a graduate electrical engineer.

I'm not book smart but I'm street smart. When I bought my house 6 years ago there was RG59 run (2 of them) that was used for an antenna. I tried to use it for my free to air system and it worked for a day before it shorted out.

RG59 should never be used for satellite instals. And as noted with both DirecTv & Dish using bandstacked technology you most definitelly need it to handle higher frequencies.

Hell I just swapped out a 6 foot piece of cable that was RG6 rated to 1500mhz....had a C-Band stacked LNB and the H side needed 1650-2150mhz and it wouldnt work at all. Swapped to a 2200mhz swept RG6 and it worked great

 

[sat.ninja]

if there is any way possible to change out that rg-59 i would do it.it will cause you problems in the future.
but i would not recomend going over to direct. dirctv is notorious for bad customer service.dish network is with in 2 or 3 channels of HD that directv has.in fact dish is slated to have more HD than directv by the end of year.
why do you want to switch ? you are better off now,i know of at least 4 house holds that switched from dish to direct and with in 6 months they all switched back,for many different reasons.

I don't know what planet you're on...If i thought Dish was better, I'd be woking for them.

 

[Newshawk]

why do you want to switch ? you are better off now,i know of at least 4 house holds that switched from dish to direct and with in 6 months they all switched back,for many different reasons.

And I know of at least twice as many households that switched to Dish and came back to DirecTV-some within days-so what's your point?

 

[Zynergi]

No joke people switch any type of service provider, comfort and familiarity are the roots of evil. You get used to how on system works, you like it and dislike the one you do not know how to use. People also switch because they didn't pay X companies bill, or just want to try something new.

I do plenty of installs where I am taking down a Dish set up... but I am very sure that many Dish installers take down Direct set ups. sh*t happens.

 

[Jimbo]

In theory, you're correct. In real world experience, RG-59 fails more than RG-6. You can believe your textbooks, but I'll believe my experience.

I think that's what he said ...
He said, Using RG-6 is preferred, but RG-59 will work as well.
My theory is, use RG-6 whenever possible, but I'm not going to rewire a whole house that has RG-59 prewired in it already.

Jimbo

 

[mykeus]

lol overheating.. thats bs.. the reason that directv technicians normally do not install hd services on a rg-59 is because of the frequency levels that the signals push at.. the new hd bandwidth levels are too high to push down a rg-59. i've even installed on rg-59 cables when i was a tech in fort worth, it works 50% of the time for a good while but the other 50% would work for a few months then you will just see the channels go one by one if not multiples at a time. it's a requirement in the installation department of directv, because the services have to be warranty to work for 90 days or they have to re-roll a hsp truck for free.