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Coaxial from HD DVR to HDTV ????

06-07-2007, 09:19 AM
I'm in a minor state of confusion here...

We're moving into a new house, which is pre-wired with CAT 5, telephone, and coaxial throughout and are in the process of working with Comcast to decided upon where the TVs and DVRs will go.

Comcast says that they've "upgraded their equipment" and that you will now be able to go directly from the HD DVR or HD Tuner to the HDTV directly through a coaxial cable (thus not needing DVI, HDMI, or component vido cables). I talked to a Comcast installer last night and he confirmed that this is now possible.

But, Sony, Panasonic, and Sharp only talk about HDMI and Component on their websites and the company that's wired the house says coax won't do it. (Vizio, however, shows a DTV connection that they say will connect to the TV through a coaxial).

So, I'm hearing different things from different sources.

Any ideas, comments would be appreciated!


06-11-2007, 11:33 PM
Why would you wanna use coax when the qulity is not there compared to HDMI ?

Some receivers have that capability but people usually only use that connection when they want to also send the signal to another tv in another room. Basically 2 tv's with the same image from 1 receiver.

06-12-2007, 06:17 AM
Although they may be technically correct, wouldn't the TV then have to have a QAM tuner to be able to decode the signal over the coax? Then the cable box becomes irrelevent, correct? I think the cable people are confused as to what's happening. Unless I'm missing something.

10-17-2007, 10:35 PM
I am also looking for a method of using an existing SINGLE RG6 coax cable to connect an HD TV to an HD receiver. However, this is a RG6 to Component adaptor or something of the sort. We cannot run cable(s) between the TV and the receiver. This is all we have. Is there a bridge from component to component using RG6?

10-18-2007, 07:52 AM
What Comcast is telling you is "most likely" the "whole truth".

Every cable company sends "some" of its contend down the coax - this has always been the case. And Comcast has been one of the better companies at providing much of their content without the need for a STB. (compared to FIOS, for example, where you are limited to 13 "basic" channels without a STB.

Now, if Comcast wishes to serve their customers well, the may be offering improved service to the sets in your home without STBs. However, there will be some limitations for sure, such as no program guide, no interactive, etc., so check again with Comcast for the details.

10-18-2007, 11:11 AM
I think they are assuming you won't be able to reconize the difference. I've never heard of this before and doubt if it exists.

10-18-2007, 02:26 PM
I think they are assuming you won't be able to reconize the difference. I've never heard of this before and doubt if it exists.


If your OTA antenna can receive umpty HD channels and send them from the roof down to your set over RG6, why shouldn't a cable box be able to send one or more full quality signals over the same cable.

Anyway, the OP still should bug Comcast to see what they are really telling him . . . .
1)Are they sending "all channels", both SD and HD to a QAM tuner? (I doubt it)
2)Are they sending a single channel, either SD or HD to channel 3 or 4? (Quite likely, and easily done)
3)Are they sending SD only, or non premium only?
4)etc., etc., etc.

10-18-2007, 02:33 PM
Why would you wanna use coax when the qulity is not there compared to HDMI ?

Coax can be as good or better than HDMI.

Consider that the signal comming into the house from Comcast is coax, and it's carrying all the channels, both SD and HD. The signal comming out of the coax at that point is the best you will ever have, and any additional processing, whether analog or digital will only (technically) degrade the signal.

So, IF the box is designed to simply tune a channel and pass it to the tuner on your set over coax, your set will handle it just like any other cable or OTA signal . . . better than or equal to HDMI.

10-19-2007, 02:02 PM
The reason why is a matter of cost and copy protection. First it does not make a lot of sense as technically it is easily done. However, the patent on the 8VSB technology to modulate an ATSC signal is still in effect, so any ATSC modulator would have to pay a royalty on the technology. Same with QAM. A QAM or ATSC modulator would allow the output to a TV or any device that had a QAM or ATSC tuner, but because that could include PC tuner cards, the movie industry insists on copy protection, thus incuring extra costs on both ends.

There is such a system in existance that uses a single coax for ATSC signals that is used for hotel systems. The TVs in the rooms have special ATSC or QAM tuners that incorporate copy protection. That had to be included so people could not hook up their PCs to the system and get protected content. That system has been discussed elsewhere on the forum.