What is the longest VGA/RGB Cable that I can run for HDTV signals? (1 Viewer)

[John Morris]

I have a HTPC with HiPix card that I use for recording HDTV. It connects to my HDTV using a VGA cable but carry's a RGB HDTV signal. How long can I run this type of cable being used for this type of signal.

Thanks for your help!

 

[Bob McElfresh]

Well to start, if each cable is a individually-shielded coaxial cable, the name-brand companies (Belden, Canare) roll out 100 feet and then brag about how little the signal is reduced. Hit the Canare web site to see the graphs.

But the problem is, the longer peice of wire will reduce the higher frequency signals more than the lower frequency ones. So you get a un-even reduction or "slant". The higher the frequency, the worse the problem. (You can tune/adjust the TV to solve some of this).

Normal video tops out at about 2 Mhz. HD signals go up to 35 Mhz - a lot more.

So you are trying to run the more reduction-prone signals a long distance. My guess is you are using a short VGA cable which does not use individual coax cables for the 3 signals. It's anybody's guess at how much attenuation you have with a VGA cable.

 

[John Morris]

Bob: Thanks for the response. Yes, I am wanting to get the HTPC, and it's fan noise out of my HT and into my office. That would mean a VGA/RGB run of about 40 feet, HD signal. Nothing else will be using that input so I could adjust the HDTV for that input but will I lose resolution at that length or pickup noise in the signal?

Canare... OK, I'll check it out and see. Thanks!

 

[Bob McElfresh]

No, you wont loose resolution or get interference (unless you run parallel to power wires or high-current equipment).

On the breakout connector from the HTPC, does it give you Component Video RCA jacks? If so, then you just need long Component cables - just being careful that the coax is rated for the HD signals. 40 feet should be no problem. (People often run longer to over-head projector systems.)