A question about Coaxial cable..

With HDTV being the new rave, there are so many variables when installing this cable in your house. RG6 or RG59, Double or Quad shielding and my big question sweep test rate.. I have seen RG6 Quad Shield rated at 1 to 4.5 GHz, what is the best for HDTV signals, or does it matter? I have 2.4 GHz RG-6, is that good enough?

I know where your server is!

Your existing 2.4 GHz cable should be just fine as long as you have good cable from a reputable manufacturer, haven't damaged the cable or have a bad splitter. None-the-less, please read the information below keeping in mind that every cable manufacturer is trying to stand apart from its competition.

RG6 Coaxial Cable
RG6 is the recommended 75 ohm coaxial cable for distributing signals from cable TV, satellite dish or from a roof-top antenna. The RG6 cable construction provides much better shielding than the older 75 ohm RG59 coax cable.

An example using Belden RG6 Cable Designs
Here is what has been published about Belden RG6 cables for indoor use:

- "Belden 3.0 GHz Duobond plus shield coax cable: Solid bare copper center conductor, Belden's patented Duobond Plus Shielded, higher shield effectiveness than quad-shielded design. Extremely flexible and easy to connectorize. Exceeds CCTV, Cable TV, Satellite, HDTV requirements."

- "Belden 3.0 GHz Quad-Shield Coax: Solid bare copper center conductor. High performance quad shielded, robust cable design, surpasses requirements for CCTV, CATV, Satellite and HDTV."

- "Belden 4.5 GHz Precision Coax Cable. Bare copper center conductor. Superior tinned copper shielded, Belden's flagship coax cable. Preferred coax for broadcast studios, and high-performance home theater applications. Provides large head-room for future high-bandwidth Cable TV, Satellite & HDTV."

But
For balance, the cable TV companies have been burying RG59 and RG6 for decades between their local tap terminal box (tap pedestal) and your house. I haven't seen them routinely replacing that cable for their new HDTV customers. I put in a call to my cable TV corporate engineering department and I am waiting for their perspective. I will post it when I get it.

It is therefore up to the individual and the circumstance as to what one decides to do.

- For example, if I was a lot younger and building a new house I think I would wire at least two spots in every room with the best possible performance RG6 that I could get my hands on. I might even install it in conduit so I could easily replace it with more advanced cable at some later date. This is all on the assumption that fiber to the house will happen in the not too distant future and that more and more devices (phones, stoves, microwave ovens, refrigerators, security system, air conditioning and heating systems and so on) will all be networked.

- If however I already had RG6 throughout my house, I sure wouldn't rip it out without carefully examining the picture on my new HDTV set first. (Preferably at the highest native resolution (720P, 1080P) but that is a whole different story.) Likewise I would make sure my coax cable was as far away from the AC lines as I could get it and only crossed the AC lines at 90 degrees. This includes the back of the TV set. If then I still had a problem, the first thing I would change would be the cable splitters.

- I changed all the 30 year old RG59 wiring inside my house to RG6 a year or two ago because the cabling was slowing the new ultra high speed modem hooking our computers to the Internet. This cable network also feeds our TV sets and FM tuners. I used all new high-end, non-powered cable splitters as well because cheap ones are a common problem. Moreover they all degrade electronically over time so I placed them where they can be easily changed. If I was going to change the RG59 cable today, I would likely use the Belden 3.0 GHz Duobond plus shield RG6 coax cable. As the great quality evangelist, Philip Crosby, put it "Quality is Conformance to the Requirements."
See what I mean? Does it all make sense to you now?

UPDATE
I have now talked with a senior corporate technical person at one of the largest cable companies in Canada and here is what I learned about their system:
(a) Presently and even with all the digital and analogue cable TV channels, music channels and Internet assigned frequencies, no frequency band is presently in operation above 1 GHz.
(b) Almost all of the RG59 cable between the cable TV companies tap pedestals and your house has been replaced with RG6 cable and the vast majority of that was swept at 1 GHz.
(c) The biggest problem the cable TV companies have with RG6 cable in your house is generally not the frequency sweep but rather improperly shielded cable. It seems that house contractors and owners sometimes cut the corners way too fine and install the cheapest, poorly shielded, unapproved RG6 cable from wherever they can find it. This is a big problem for cable TV companies because they are left to sort out the problems with an irate customer.
Thus in conclusion, in today's world and referring back to our RG6 cable examples above, the Belden 3.0 GHz Duobond plus shield coax cable would be an excellent choice for the replacement cable in your house if indeed the older CATV cable actually needed replacement. I welcome others with more expertise and experience to correct or add to this information.

Sincerely
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

Peter,

The following link explains a lot about HDTV cables. It is non-technical and even I basically understood it. rb


www.bluejeanscable.com/articles/hdtv-cables.htm

Hi Richard,

You have certainly been posting underground these last few days.

Good point but to make sure that all readers are on the same page, we are exclusively discussing the SDI (Serial Digital Interface) RG6 and RG59, 75 ohm impedance coaxial cables. These are all on the signal supply side of the HDTV set.

WE are not discussing any other HDTV cables such as the now obsolete DVI (Digital Visual Interface) cables, component cables and HDMI (High-Definition Multimedia Interface) cables. These cables are the various hardware interconnect cables and although mostly very different in design, are similar in concept to the stereo hardware interconnect cables we all know so well.

HDTV Defined www.engadgethd.com/2005/10/22/hdtv-defined/

Best personal regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

OK, let's continue on the subject

So why is there such a big hype about having RG6 sweped at 3.0 GHz and above for new houses when the infrastructure is not even up to par. Is the industry just feeding consumers crud to buy more expensive products?

I understand that HDMI cables have a certified maximum distance of about 30 feet. So from a HDTV cable box and a HDTV sitting 50 feet away the best choice still is then component cables. Even though they are analog will reach far past HDMI lengths, correct?

To answer your first question, I will respond with another question. Why do people spend money on very expensive cars including sports cars that can go 200 miles per hour with big V8s and terrible gas mileage? The answer is that there is a choice and there is marketing. We already know what the cable TV companies would say in response to your question but at the same time I would imagine that today, there is very little if any cost difference between a RG6 cable swept at 1 Ghz and one at 3 GHz. So go with whatever you feel most comfortable with. I certainly cannot speak for the RG6 cable manufacturers but technology always improves.

Moreover, keep in mind that the house contractor is advising you that they installed high quality RG6 cable when they built the house. (See the cable company problem "c" above.)

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As far as your HDTV converter box goes, I would want it quite close to the TV set and certainly not 50 feet away. I don't think you would get a straight answer from anybody re your question of long runs of HDMI vs component because of the possibility of interference. BUT you might want to look at the write up here www.bluejeanscable.com/store/hdmi-cables/index.htm on Belden BJC Series-1 Parallel Digital Video Cable. They say they have run 1080p/60 video 125 feet without degradation on this bonded-pair HDMI cable. I use short runs of (say 12 foot) component cable (I'm cheap.) and they work just fine but I am very careful to keep them away from AC cable(Remember the 90 degree crossing?).
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Here is another one for you. Why would somebody pay $160.00 or for a 12 foot video cable assembly for say their HDTV when the cable is worth say $2.00 a foot and the connectors say $10.00 each installed? That is the ultimate in marketing and I'm sure you know the company I am referring to.
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Marketing can be fascinating:

- I was recently at a car show where one guy had a restored 1958 Chevrolet red Impala convertible. The restoration parts alone cost almost $50,000.00 because they just had to be new-old stock and he was bragging about it. I was listening and thinking what P.T. Barnum used to say and that was before the population explosion. It meant that a single chrome emblem outside the car cost in excess of $450.00 instead of a Taiwan identical replacement for $90.00.

- I also remember the Volkswagen ad that showed a guy driving a brand new luxury yacht off a dealership lot and the commentator is saying "This man will lose 30% of his investment as he crosses the dealership property line and our question is: Why is he smiling?" The answer of course is marketing and that brings up for me the best automobile commercial ever made. It's all marketing and every scenario at the time is in it - 3 minutes long with sound.

Everybody is different in their desires, values and beliefs and I think that pretty well wraps up this thread.

Sincerely
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com