Simple (?) Coax cable question

[Champagne taste beer budget]

Can someone easily explain to me the difference between the different coax styles, i.e. rg6, 58, 59, etc?

I'm sure it's been expailed here before, but with the search feature on vacation, almost all the hits I got were comparing coax to optical.

Thanks.

[yaffstone]

They are different in impediance. This is important for RF and high frequency feeds such as cable. You'll not hear the difference in audio applications such as patch cords.

[Champagne taste beer budget]

ok, so in a whole house distribution system, which would be preferred, and why?

[3dzapper]

TV or audio? For TV or cable, RG-59u 75 Ohm co-ax.

For sattillite (Direct TV, etc,) you need a special 3 wire coax from the box to the antennea to power the LNB(s).

For audio, a four wire 14 or 16 guage cable. I hate to mention any names but that baaad company markets a good quality. See it here (link).

In bulk..

[Smokem]

What is the number of the coax need for Satellite?

[IAmtnbikr]

"For sattillite (Direct TV, etc,) you need a special 3 wire coax from the box to the antennea to power the LNB(s)."

Not to argue....but plain and simple old RG6 is what you use to get from the receiver to the dish, not a special cable with an extra conductor; no such thing is required. There are multi-LNB dishes that support more than one satellite, and there are switches that let you run multiple receivers off a lesser number of feeds from the dish itself. The reason they recommend RG6 over RG59 is the larger conductor and the fact that the coax is carrying the voltage signal from receiver to the LNB's. There can be signal loss using RG59 if the run of cable is long enough. You can usually use it once inside the house with no ill effects though.

edit....go here for some interesting reading:

http://www.epanorama.net/documents/wiring/cable_impedance.html

[3dzapper]

I could be mistaken. It wouldn't be the first time and definately not the last. When I installed my Direct TV system back in the nineties it required this 3 conductor cable. Like RG-59U and a separate power conductor:

Rick

[IAmtnbikr]

Most likely that is an extra ground circuit to use. I did our Direct setup with a triple-LNB dish about two years ago and ran a pair of dual RG6 runs underground from the dish to the house. The voltage is sent through the center conductor of the coax to the LNB's.

[3dzapper]

I did that in like 1988 and seem to remember a mention about power in the manual. Obviously I no longer use it or I would look it up. That is jut a little piece left in the outside sheathing when I cut it out. I now have new siding or there would be daylight right under the electrical panel.

[Champagne taste beer budget]

Thanks for the replies. I was downstairs the other day and noticed that on the side of the 250 spool I'd bought when I wired the house runs and out to the OTA antennea it was RG6. I really hadn't paid attention to it when I bought it, just got a spool of coax. Looks like I'm ok, wouldn't want to run new wires everywhere, but if needed, would rather do it now instead of after I cover up the ceiling downstairs. Nice to have access if anything needed to be changed.