How come coax cable does not have the same picture quality as other television cables?

I honestly think all these different cables for HDTVs are just a ploy to make more money. Component better than S-Video. HDMI better than component. What a load of crap! Your HD-quality video comes into your house through a coax cable (usually). Suddenly you need special cables to run from your cable box to the TV?

I get the fact that the HD-signal coming into your house is digital, and the cable box deciphers the signal. But what I don't get is that now the high-quality signal can no longer be carried via coax from the box to the television. And these so-called digital televisions can't extract the high-quality video?

Simply put, why can't coax from a cable box to television carry the same high-quality signal that it first carried into the house?

You can use coax to carry signal from a HD Box, I've done it on more than one occasion when installing cable. Honestly you can't even notice that much of a difference between coax, Compenent, DVI and HDMI, Coax is used a lot when hanging High def tv's because of the distance from the box to the tv. Its hard to find the hdmi and compenent cables that will reach that far so you can use a coax and just get an adapter from any electronics store that will let you plug the coax into the compenent video plugs.

The coax cable for today's new technology has to be fiber-optic cable, not your standard, out of date coax(anolog) cable.

Coax carries radio frequency. But the signal that comes into your house is different than the one runs from the cable box to the TV.

The signal that comes into your house contains dozens of different channels, each at a different frequency.The cable company has rooms filled with racks of transmitters, each sending one channel at one frequency. If you have digital cable, you can compress more on each channel. In either case your cable box tunes/decodes these.

coax serves a different purpose when it leave the cable box (or VCR, or other device). Unlike the cable company, your box has one very low power and cheap transmitter for either channel 3 or 4. Signals sent in this manner are of poorer quality because all the video information (color, brightness, etc) and all the audio information are just within that one channel. It usually isnt even stereo. I suppose cable boxes and DVD players could encode the output as the digital channel 3 or 4 but they would be very expensive.

The other cables you mention are, in fact, better. They all use some form of spreading out the video and audio info so it's put together right at the TV.

The scam in all of this is the different kinds of HDMI, component, etc. Monster cables, gold plated nonsense, etc. is the real crap.

hi there,

A coaxial cable has only one inner conductor to carry a signal. However a coaxial is great for sound and that is what they use to carry 5.1 digital audio trough digital coaxial cable.

But when its comes to picture quality, a video signal(regardless weather its digital or analog) is made up of red, geen, and blue. On a coaxial cable, all of the 3 colours are carried on one conductor along with the sound signal. On composite cable, its the same story but the audio is carried via different cable and thats whay composite is slightly better than coaxial. Next is S-video, this time black and white are carried separtely and the other colour seperately as well (audio is carried on different cable). S- video is much better than composite. Next comes the high definition picture quality, component cable (analog) carries the 3 colours seperately on 3 cables and audio on a different cable. Next comes the DVI (digital visual interface) and HDMI (high definition multimedia interface) DVI carried true high definition video in digital format, but the audiot has to be carried seperatley. HDMI is the same as DVI, but this time audio is carried on the same cable digitally. When its digital its doesn't matter how many conductors you have. 1 and 0 stays the same no matter what.

Hope this helps.

It certainly can. Coaxial RF cable from an Hybrid-Fiber cable plant can carry voice, video, and data all of digital quality.

By using an HDMI or component connection you eleminate the remodulation of the signal from the baseband video that the cable box has stripped off the cable companies QAM signal, back into an ATSC or NTSC signal that your tuner can demodulate. If you go strait video from the cable box you should have a better signal to noise ratio.

Its not the tv's fault, most tuners only pick up ATSC/NTSC signals that use a completly different modulation scheme to represent the digital 1's and 0's then the cable companies digital compression with QAM.