Originally Posted by Hopps
Thanks. I have to admit I typically believed that coax was coax coming from a CCTV background. I was used to using rg59 and rg6 with bare copper braids for all my coax needs. Now that I wont be able to remove most of it once it's installed I'd like to be a lot more careful with my wiring decisions. I will be installing a couple 1-inch conduits between the family room TV and the AV cabinet for future wiring. I'd like to make the right decision with the coax so I don't have to start using up my conduit prematurely.
I've installed antenna wiring for about 40 years, going back to when we often installed unshielded twinlead. I've also installed satellite wiring in big buildings, carrying those high frequency signals as far as 1/4 mile.
From a signal transmission standpoint, coax is coax. Some coax has a little more loss over a given length than does other cable, but unless you are in an incredibly demanding situation, like trying to simultaneously distribute off-air signals that vary in signal strength by 30dB or more AND wind up with a distribution budget insufficiency that leaves you exactly short a dB or two, then cable won't make a difference from a signal strength standpoint.
Better quality cable can make a difference in four ways.
1. Foil shield will resist signal ingress much better than really old, braid-only shield wire, but the only braid-only shielded wire I have encountered in the last decade was RG59 intended for security camera use... and a few TV jumpers with molded F connector ends that were supplied with consumer electronic products.
2. Quad shield MAY make a slight difference in egress, or broadcasting, of your signal, but you will have no reason to care about that. Cable companies care because they are held accountable for cumulative system leakage but even then, I think their preference for quad shielded cable is not so much because it tends to leak less in normal use, but rather because even if it is whacked and the first foil shield layer gets breached, the second layer remains intact.
3. Systems that count on coax for powering gobble up more current and drop more voltage if they used higher resistance, copper plated steel center conductors and less dense shielding. That used to make a big difference when trying to have a satellite receiver toggle a polarity switch over distances of 300 feet or more, but is not that important for most household situations.
4. A decade ago, I did some work on houses that a developer had prewired that had outer jacket material that became so brittle when frozen that when I bent it just to hold it to dress the ends, it split off like a snake sheds its outer skin. I don't know how common it is to encounter junk like that, but it was that way at several houses I serviced in the same development.
As you might imagine, I always buy price when I buy coax, and have never been burned for having done so.