sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Tracing or Toning Unterminated Shielded Data Cables - Needle in a Hay Stack

600+ CAT6A shielded cables (F/UTP) dangling out of the drop ceiling in a hospital, all nicely bundled in groups of 24, and ready to be laced in to the patch panels but several bundles have duplicate numbering.... This stuff is difficult to tone out.

If I'm at the station end with my unknown cable and I strip back all conductors and twist them up to make a larger conductor, place the red alligator clip to the conductors, and the black alligator clip to a ground at the station end (metal framing, electrical box, ground prong etc.), what happens in the MDF is I get terrible bleed on every cable. If I take the black alligator clip off of ground, and say split up the conductors 1/2 on red and 1/2 I cannot find the cable. Done this way, the only way my probe can pick up the tone is by getting it within 1" from the cut end of the cable.

I've experimented with red on the copper and black on the foil shield that wraps the conductors, red on the foil and black on ground, etc etc.

Only two results: no tone, or too much tone bleeding all over every single darn cable in the room.


What's the trick to toning shielded cables?

Thanks!

There is no trick. I think your doing it wrong. Take the blue/blue white pair at the station end. Skin back, put 1 clip on 1 blue and the other clip on blue/white. Make sure they don't touch each other.

At the future patch panel end, take your probe and touch securely the cut end of each cable till you find the tone. There should be no spill over this way.
Time consuming yes but it will work.

The trick is to use a split pair. Since the reason that cables use twisted (balanced) pairs is to reduce crosstalk, and your probe is essentially trying to detect a leaking signal that is similar to crosstalk, you need to use 2 wires that are not a pair.

Try putting one toner clip on the white/blue wire and the other clip on the white/brown wire. Do not ground anything.

Let us know how that works.

Another trick, born of desperation, is to examine very carefully, and document, the color, texture, and foot markings on the sheaths. In a large job, unless the installer had access to a billion feet of the same type of wire, chances are that the cables will have come from different manufacturing lots. The foot markings will help narrow down the choices.

If you find one cable out of 24 successfully, and you have a blueprint of the building, by process of elimination, you have a better chance of finding the subsequent cables in a 24-cable group as you find each one. If you are stuck finding the first one, try sending on another. It's often just luck to find the first one. But then, you will have the aural reference and will know what to listen for (in terms of volume, cadence, etc) on the rest of the cables.

Do the testing in a quiet room. Turn off the radio that the plumber is listening to. Shut off as many fluorescent lamps and fans as possible. Chew gum. (I am not making this up. It tends to pop your ears and make them more acute.)

Visualize how the cable is laid up. The wires are not only laid up in pairs, but the pairs are arranged in a big twist, too. The wires you're listening for appear near the jacket only every 6 or 8 inches, periodically. Move the probe slowly along the jacket. The correct cable will have areas of loud signal, and areas of no signal. Be patient.

I have used all different sorts of toners in my 50+ years of doing this. The best one, IMHO, is the original (not the later "improved" one) orange toner made by Aines. (See photo for the exact one I use).

https://www.aines.com/media/aines_tg1.gif

Another even more desperate and time-consuming method is to go to the far end of each cable. Short-circuit the white/blue pair in cable #1. Short the orange pair in cable #2, and so on.

Then s/c the white/blue wire and the white/orange wire in the next cable. Keep doing this until you have used up all the combinations. If there is a handy ground connection near each distant end, continue and ground one wire in each of 8 more cables. Use a test lead with two alligator clips and go from the center screw in a receptical faceplate for the ground source.

Write down the colors and the locations on a note pad or on the blueprint. Use a meter to find the shorts and grounds.

This method, while time-consuming at first, will allow you to find and eliminate a few cables from a group, reducing the chance of finding the wrong cables as you go on through the whole group.

I've had success using a full pair, one clip on 1st pair other on 4th pair, or which every you choose. Like Arthur said the twist of one pair will knock your level way down at the far end.

I want to reiterate what Arthur said about toners and probes. With everybody getting into the act these days there is a lot of junk out there and the proper equipment will either make your job easy or impossible. I have always used exactly what Arthur uses and if you aren't an old telecom guy you probably have no idea who Aines is. Notice the metal tip on the probe? I second one of the methods of sticking the probe into the end of each cable but if you try that with a probe with an insulated tip it ain't gonna work (assuming that the probe itself has sufficient amplification).

-Hal

Good discussion here. Be sure you have new batteries in both tone and probe for a job
This size buy a box of 9v and keep a eye on voltage

I don't envy you at all with all that 6A shielded, I'm assuming probably plenum rated too since it's healthcare.

Having four different types of tones helps doing high quantity tracing as long as you've got a system to keep from forgetting which is what.

A buddy on the other end with a radio or cell phone makes tracing it a LOT faster.

Ever hear of Tumidor? I happen to have one which was liberated from Bell Telephone. This provides exactly 1 KHz at 0 db. It has a +10 db switch on it. Cable repair techs used these on spans several miles long. You can, quite literally, hear the tone with the probe two feet away.

It's not fancy, but we did a large job for the housing authority with 600 CAT 6 cables in a similar situation. The bundles corresponded to locations. I put the Tumidor on one pair of a bundle and walked down the corridor until I heard the tone in the probe. I was, at least, 4 to 5 feet away. Once I heard the tone, I knew which bundle went to which location and finding the rest was simple.

I know why Bell discontinued using the Tumidor. Subscribers would complain that there was this "noise or tone" on their line. The splicer could be miles away working on a different bundle and the tone was audible. The trick was to learn how loud it was to determine the correct cable.

Rcaman

This is shielded cable and that will cause problems tracing it.

Are the far ends terminated? If yes, the I would suggest what you need is a cable mapper with multiple remote ends like the Platinum Tools T129 VDV MapMaster and optional T121C Twisted Pair/Data Remote Set, 19 pc.

https://www.specialized.net/Special...ter-20-Voice-Data-Video-Length-8940.aspx

This is just and example.

The fact the the cables are in bundles of 24 tells me that each bundle goes to a specific area and once you find a couple of bundles far end you should be able to see a pattern emerge. I would also add that this is a two person job in my opinion

Not trying to bad a hardass, but I see you're from California. Due you have a proper Contractors license for doing this job?