Different qualities of RG-59 Copper Clad

My work has had me become very familar with the different grades of RG-6 Cable "60%, 90%, Quad Shield" and their properties and applications. To date I have only used standard RG-59 Copper Clad for the small CCTV installations I have been involved with. Do they make different grades of the stuff? At my distributors, they carry standard RG-59 along with mini sized cable. When ultimate shielding is required, do you just step up to RG-6 designed for CCTV "do they make a version designed for CCTV" ???

I have thought of asking this at the distributors, but they are often like Radio Shack "You Have Questions, We Have Blank Stares"

RG59U copper braid generally comes in two qualities. Low cost is about 70% braid and best is 95% braid. The price difference is very little so it is best to insist on the 95% copper braid cable.

When I wired my house for video (component HDTV distribution and security), I had just assumed RG-6 quad would be the best choice for any type of video transmission.

Why is it that copper shielding is better for transmission of CCTV signals?

CCTV video transmission is at a different wavelength than RF transmission and aluminum is a poor conductor and poor shield at those frequencies.

I'm sorry that I don't know the exact frequencies involved but this has been from many years of experience in both the RF and video industries.

When RF is transmited over a coaxal cable, the cable is working more as an enclosed guide or wave path for that RF signal. That is why a sharp bend in coax will cause "reflection" and hinder the signal. The ohm rateing being crucial to accomodate different frequencies of RF signal with those of CATV working best with 75 ohm

CCTV is a very low "line level" signal and is actually using the conductors of the cable as any voltage current will and with copper being one of the better conductors... Coax providing the best protection from voltage inductance and infultration of RF signals.

Hence many of your high end Video Interconnect cables will promote the inner conductors being Silver and even Gold coated along with the end connections themselves. Granted my training in such matters was many many years ago so I may be getting things backwards or downright upside down ...

I never stop learning new things in the forum. Thanks much!

A related question: Is the cable type also a factor when distributing a CCTV signal from the monitor output of a DVR to the monitors?

I'm grateful for the chance to pass this on. I certainly couldn't explain it any better.

http://www.westpenn-cdt.com/pdfs/coax_train.pdf

And here's a page for thier other tech bulletins.

http://www.westpenn-cdt.com/techinfo.html

I really like the fact that WestPenn published so much tech info on their website.

Great link. Explains things very well. And yes in answser to the question about distribution amps, use the same cable.

Excellent resource. Thanks very much, bryan1656.