How do I tell which coax if for what?

A tiny piece of alum. foil inserted into one end of the coax so the collar and the center conductor short out will allow you to use a multi-meter at the other end of the available coax cables. When the meter shows and open short you know you have found the right cable. Even finding multiple cables that beep let you know they are connected somewhere via a splitter. Generally, all the coax connections will be separate except the outside Cable TV connection which might run through splitters other than the wall plate with the power supply for the OTA TV antenna.

Bmcgough3 wrote:
Thank you! I guess I’m going to buy a tester today.

With all coaxes disconnected, stuff an F connector full of tin foil, and barrel connect it to a coax in question. Then go to the other end check for continuity.

A bit of left-over coax, some cable ends, a battery, and a flashlight bulb, and you can make your own tester is just a few minutes. connect battery to coax, add a connector. connect light bulb to another piece of coax, and another connector, and you are in business. connect batter to one end of unknown cable, attach light to all other ends until it lights, and bingo! Be sure to add markers to the cables after you identify them.

Thank you! I guess I’m going to buy a tester today.

Lynnmor wrote:
Of course you could use an alligator clip and a cheap, (sometimes free) ohm meter from Harbor Freight to do the testing.

The trouble with an alligator clip on the signal lead is that it will sometimes lean against the barrel nut and make a connection to the shield. Then all wires will ohm out if they go through a splitter.

Of course you could use an alligator clip and a cheap, (sometimes free) ohm meter from Harbor Freight to do the testing.

I agree with the tester. Though I do not have/use one myself (how I do it is a lot more work) but that is the easiest. There are two types of testers.

One is a radio transmitter with a directional receiver. You hook the tranmitter to the wire (Shield or nut or sleeve) and then "Track" it with the receiver. This will tell you WHERE teh cable goes but if more than one cable goes there...

The other one is a tone generator (Audio) and a speaker... You hook the generator to say the cable in the bedroom. then test each cable at the entaintement center and the one that goes BEEP.... Lable it "Bedroom"

then move the sender to another cable and repeat.

Several years ago I got a gizmo called a “coax explorer tester” at Home Depot. It will identify 4 cables at a time. You connect the 4 sensors to 4 cables then connect the tester to your best guess of where they go and it tells you which one is right.

I forget what it cost but it wasn’t huge and I’ve needed it about a zillion times since. I seem to have a knack for disconnecting cables and getting confused about which is which, even after attempts at meaningful labeling.