I know this is probably an old question but I can't find anything about it on the site.

Why use RG-59 instead of RG-6 for baseband audio and video signals? If I could use RG-6 for everything that would be much more convenient but I know that the transmission properties of the two types are different. We were once told at a CEDIA seminar that it has something to do with skin effect and the material the coax is made of. Is this really true?

Hoping there's an engineer here with real knowledge of transmission line who can clarify this for me once and for all.

Thanks!

Just use all copper center RG-6. The copper coated steel is ok for the higher frequencies of cable TV, but baseband video and audio signals travel better on all copper.

RG59 is not inherently superior to RG6 assuming both are copper center conductors. RG59 is less expensive and as a practical matter will transmit video without loss the limit of a composite video signal. On very long runs the larger gage means less voltage drop but since you are not supposed to run composite video more than 75-100 ft it matters not. Personally I use only RG6. Copper coated steel for RF and copper for baseband.

Alan

The shield material is also important. Most RG-6 has an aluminum foil/aluminum braid shield. Aluminum is not solderable, copper is; plus aluminum oxide is non-conductive, while copper oxide is conductive.

Also, RG-59 is easier to find connectors to fit and more flexible. In my opinion, RG-6, especially quad-shield, is too stiff for typical interconnect use. For a long in-wall run, I'd consider RG-6, but all-copper is a must.

My bottom line is RG-6 for RF, RG-59 for all else.

That's great information and it's all much more clear to me now. Thanks! It's nice to have access to real expertise here..

That's a very valid point, that RG59 is easier to terminate for audio/video connections and is solderable if the shield is copper. For that reason alone, it's worth using. So that's it, I shall carry the two kinds from now on to serve their purpose.

It's astounding to me how many pros don't understand this. These responses are all dead on but the number of times I run into installers that don't have a clue about the difference between CCTV wire and CATV wire...

The difference is that RG6 is usually RF cable TV wire and RG59 is usually Closed Circuit TV wire. When you order wire for video, camera's or whatever, you need to state CCTV wire, whichever gauge you choose. That should gaurentee copper center and copper braid.

Incidentally there are some CATV RG59 wires out there with much better specs than the average RG6. very, very flexible and easy to use just three times the cost of your average RG6