coax cables carry hd?

superdude882

ok so first off, if you don't have cable or satellite you can simply use an antenna and hook it up to your hdtv w/ tuner to get hd channels correct? so does that mean your regular plain old coax cable is capable of carrying hd signals? so why do we bother with all the component/hdmi junk?

Scottnot

Yes, that's correct - plain old coax is capable of carrying HD signals.
The antenna receives signals that have been RF modulated over a frequency range of 54 mHz to (formerly) 890 mHz and delivers ALL of the available over-the-air channels to your set simultaneously.
Each channel requires 6 mHz of bandwidth, so the "plain old coax" can not only carry individual HD signals, but a great many of them as well.
The tuner in your TV selects the correct channel, demodulates it and converts it to an appropriate format for display.
In the case of set-top-boxes, the tuner selects the correct channel, demodulates it and converts it to the correct format for transfer to another audiovideo piece of equipment in one of several standard formats - composite video, S-video, component video, or HDMI.

Component and HDMI carry the signal in somewhat different formats, and carry only one channel at a time; Component is analog and HDMI is digital. A full HD signal in Component format requires about 35 mHz of bandwidth at "baseband" (simply put, this means that the signal operates from 0 - 36 mHz on a cable that is designed to carry up to 1,000 mHz . . .

Component cables are, in fact, nothing more than standard coaxial cables (RG59 or RG6) terminated with RCA connectors rather than "F" connectors.
Component cables are only capable of carrying video, so when using component, it is necessary to run additional cable(s) for the audio portion of the signal.
Component is capable of carrying full HD and delivering excellent picture quality to display devices. Its benefits are that it is inexpensive, very robust, and can carry signals over long distance (> several hundred feet).
Drawbacks are that it requires multiple cables and separate audio.

HDMI uses a "single" cable to carry both video and audio, so has the benefit of being simpler to use and less bulky.
Drawbacks are that it is (typically) limited to shorter distances (less than 50 feet), and has "interface" problems with some HD equipment.

Hope this helps.

freebird77

Does that mean that the old rg6 cable I have from my current sattilite, will work when they come out to install the hd on my new tv?
Im wondering if we are going to have to dig a new trench if the line has to be replaced to recieve hd? I see where it comes through the floor it says rg6.

Scottnot

You're actually asking two questions here . . . sort of.

First, for the simple answer: RG6 is just fine for "most" applications.

However, some satellite systems require either "rated" RG6 or even dual cable "rated" RG6 because they carry the signal from the antenna to the receiver at satellite frequencies as high as 2.5 gHz.

So, if you are upgrading your satellite service from SD to HD, you may very well have to upgrade the cable as well. Good luck; I'm sure the installation guys will know what is required for your particular case.