I have a bundle of coax cables coming out of the wall in my living room and another bundle coming of the wall in another room. How do I test a cable so I know which end goes with the other?
Thanks and sorry for such a basic question.

 

I have a bundle of coax cables coming out of the wall in my living room and another bundle coming of the wall in another room. How do I test a cable so I know which end goes with the other?
Thanks and sorry for such a basic question.

I used to do it the hard way. Put a signal on one and then see which cable has a signal on the other end.

You could also hook a battery to one end and use a lightbulb on the other.

 

Battery. Meter. Alligator clip jumpers. Partner. Tape. Marker.

 

Disconnect all of them.
Using aluminum foil short out the pin and screw cap, you
know make sure the pin and screw cap are connected with foil.
If you have or can obtain a continuity meter touch the
pin and screw cap on the other end of each coax until
it lights up, viola, then youll know which it is then tag it.

 

I have a bundle of coax cables coming out of the wall in my living room and another bundle coming of the wall in another room. How do I test a cable so I know which end goes with the other?
Thanks and sorry for such a basic question.

yall beat me to it.

 

How do I test a cable so I know which end goes with the other?

If you put a different resistance on each cable, you can do them by yourself and all in one pass (by measuring the resistance on the other end).

 

If you put a different resistance on each cable, you can do them by yourself and all in one pass (by measuring the resistance on the other end).

Well now you’re just showing off.

 

A continuity test is iffy. A voltage test lets you compare cables. You will notice any outlier.

 

A continuity test is iffy.

Why?

 

You can't be sure of the location of the continuity.

 

You can't be sure of the location of the continuity.

You mean if the cable is somehow shorted?

 

Yes, or even multiple shorts. When using continuity, one needs to check the cable for non continuity to be sure. Two tests.

 

Yes, or even multiple shorts. When using continuity, one needs to check the cable for non continuity to be sure. Two tests.

I don't follow your logic.

If a shorted cable is used with the method I proposed, it would show as shorted. If it was open, it would show up as open. Either case would require more investigation. A good cable would measure the approximate resistance (depending on length) of the resistor at the other end.

Your method is more work and would still require further investigation if there was a discontinuity.

Multiple shorts, multiple opens; who cares. The OP just wanted to identify which ends went together. If any had shorts or opens, the cable isn't usable.

 

dl324.....my response was referring to a continuity test. Your response to me.......is a resistance test.

Two different things. Two known batteries or two known resistances will both indicate cable quality.

If you use two......it cuts the number of walking oscillations to 1/2 the number of cables. Half are tested and set up on one side and half are tested and setup on the other, with one man.

Does that make any sense?

 

Does that make any sense?

Still doesn't make sense.

Why can't I put a 100 ohm resistor on one end of the cable and measure it on the other end? Cable resistance would increase the resistance, but whether the cable is open or short isn't relevant. The OP is just trying to identify which ends go together. If there are opens/shorts, that's a bigger problem.

With my method, you terminate each cable end in one location with a different resistance. Then you go to the other ends and start measuring resistances and labeling cables. You still have to walk back to the ends with the terminations and remove them (and label the ends if you didn't do it when terminating). One round trip and you're done. Assuming there are no opens or shorts.

 

I will try again. I did not say a resistance test was iffy. Continuity is iffy. A dead short is iffy. A resistor is not iffy. A resistor test will do fine also.

I like resistance. It's the short I don't like.

 

In the original questions, there is nothing to suggest that there is anything wrong with any of the cables. Also, there is nothing about connectors on either end. I think a dead-short test is fine, but a simple open circuit measurement of all cables as a first step will find any problems before then confuse the identification.

ak

 

http://www.pansco.com/index.php?do=prods&id=61 or similar.

This time label the cables.

I did some labeling at work where I used a location and a cable #.
Locations were alphabetic, cables had numbers.

So, A11B (B=current location) is one end of the cable and (B=goto location) B1A (A=current location) is the other. It would be cable #11.

I had plastic alphanumeric labels. The cables were Fire Alarm Cables. My system interfaced with the fire alarm.

The wires were not home run, so I needed something better.

I didn't have to pull them.

TV cables are home runs, so they can be labeled as Hall-1 or Hall-2. I try not to be specific as TV-Kit and TV-LIV, they just need to be referred to as cables. The use can change.

Cables to the attic I have to be careful with. 4 were pulled. Two are used.
One gets a power injector in the attic and is eventually the UHF/VHF feed.
The other coax runs the rotator.