We have a tone generator kit for tracing network cables, but I am having trouble using it correctly.

The tone generator end plugs into the network cable I am trying to trace, and then I assume I should be able to go into the server room and just swipe the probe across the ends of the patch cables while still plugged into the switch, and hear the tone, but that doesn't seem to work.

  • When the probe is pointed directly at the tone generator, it responds correctly.
  • When I point it a few inches down the wire that is connected to it, it does not respond. I suspect this is due to the cable shielding? As a result, I assume I need to point at the cable end, and not the middle of the wire in the server room.
  • My understanding is that the probe does not require you to un-plug any cables to work. Is this correct?

It would be great if someone who knows what they are doing would document the correct procedure here.


11 Answers 11


First, check the batteries or make sure that you have new ones. Next, you should be swiping along the patch panel and not the switch. I swipe along the underside of the cable jacks (against the copper side) or along the punch panel on the back. I usually get a clearer signal this way.

I think you should test your toner by plugging the generator into a line you know is patched properly and stick the receiver in the proper jack.

  • Thanks - swiping along the back of the patch panel did the trick. Unfortunately it's a pain to access!
    – Brent
    Jun 4, 2009 at 16:53

My experience with tone generators is that you're going to be touching the pins on the jacks on the patch panel, or, if you've got a really sensitive probe, the terminations on the back of the patch panel. I've never used a tone generator / probe combination that was able to pull tone thru the insulation of a UTP cable.

I don't know that I'd plug a tone generator into the far end of a cable that's patched into a switch, either. You probably won't blow anything up, but I wouldn't try it.

  • I've got a fairly low end "fox and hound" that I've used to find a cat5 cable inside a wall through sheetrock. I couldn't tell you it was two inches to the left or anything, but I could tell you that cable run somewhere near a given section of wall. I got a faint sound, but it worked.
    – kbyrd
    Jun 4, 2009 at 16:33
  • 1
    Yeah-- I'm reading about some of them here working thru walls. Wild. Apparently the one I have is crap, because I know it can't do that! smile Jun 4, 2009 at 16:56
  • Last place I worked had a Fluke tone generator, just standing in the same room as the cable made a faint noise, and it got steadily louder until you were touching the right wire. Absolutely fabulous for ancient buildings with weird old wiring and conduits like Pan's Labyrinth.
    – Chris S
    Nov 27, 2014 at 2:08

All the above have great ideas, but another option is the following:

If you are trying to trace out Cat5 or 6 cabling, make up an adaptor that bridges/shorts out both the blue and the orange pairs and then connect the whole blue pair to one alligator clip and the whole orange pair to the other alligator clip. This will increase the tone volume significantly, as the twist in a pair of cat 5/6 cancels out the tone, but shorting the pair and using both conductors it overcomes this.


If you are tracing a data line, you have to disconnect the patch cable from the server to the patch panel. If you do not disconnect the patch cable, you will get no signal from the tone generator. The server interferes with the signal. Also, mentioned above, make sure the batteries are good in the tool.


Certain toners or network testers mainly high end fluke brand ones will tone through a live patched cable.. Most other toners are not very practical on "live" lines. But are great on lines that arent patched into anything at all (fresh install)


The 'wand' end of the tone generator usually has a 'gain' adjustment. Make sure you adjust this appropriately for your environment. It depends on physical contact with the copper if the signal is faint, although I've traced wires across an entire building and not needed

When you have a lot of interference (active network connections) or jacketed / interference-resistant cable, you're going to need conductive contact between the wand and the actual wires inside the cable.


You can trace the cable that is plugged into a switch or server but you must ground the black alligator clip that come off the tone generator. Any large metal object should do the trick.


Cut a patch cable in half and only connect one toner lead to one wire. When the cable is plugged into a switch you must only tone a single wire not a pair


take a patch cord cut it into, next remove about 2 inches of the outer shielding to expose the twisted pairs, cut off the blue/white pair, orange/white pairs, and the white wire from the brown/white pair. this will leave you with the green/white pair and the solid brown wire, next remove the shielding from all 3 wires twist the green/ white pair exposed wires together. place 1 of the clips from your tone generator to the green/white pair and the other clip to the brown wire this will allow you to short out the active port on the switch so you can tone out the cabling without harming the port on the switch.

  • Too intrusive to my liking... May 16, 2015 at 15:31

Data switches and computers "eat" the tone when applied to the twisted pairs. 1&2, 3&6, 7&8, 4&5. when toning out the cable use split pairs. For example apply the tone generator to pins 2 and 7. THIS WORKS GREAT!


Testers are getting less costly every year to test and trace active cables. Rather than taking a chance of burning up a clients switch buy one or find an older unused switch and do your testing as shown above on it. Just saying.

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