Cable Tracers

Cable tracers are used for tracking and troubleshooting cables quickly. They are suitable for identification and maintenance of telephony networks and also for testing any kind of lines not-connected to the mains. Suitable applications are wiring test for computer Local Area Networks (LAN) and telephony extensions.

There are countless cable tracers on the market, but they all operate on similiar principles. They transmit a signal on to the cable and have a receiver that detects that signal.

Method: use the tone generator and the probe to determine where a cable is going and whether or not (and where) the cable is interrupted.

The Tone Generator is a hand held, battery powered instrument designed to perform a variety of tests on unenergized telephone lines or LAN cables. Alligator clips and a standard RJ11 plug allow the tone generator to be connected to stripped wires, terminal panels, wall plates, or modular single line jacks. The Tone Generator usually generates continuous tone or warbled tone with selectable test frequencies. Frequencies are usually around 1kHz frequency.

Here is a video that shows how to use Tone and Probe Cable Tracer.

The Line Tracer is a hand held inductive tracer that will help to identify wires without piercing the insulation. It can trace Tone Generator signals through dry wall, wood and many other non metal surfaces.

The conventional use of the inductive amplifier is the location of breaks in hidden wires, even buried in concrete. The typical wire detection range in a concrete wall is 10-20 cm. One of the manufacturers of the inductive amplifier is Tempo. Inductive amplifiers can also be used to find an individual cable pair in a telephone cross connect or cable head when used in conjunction with a tone generator.

Inductive amplifier can be used to trace mains wiring inside the wall. In case the mains wiring is is or can be reliably disconnected from mains power source, it is possible to trace disconnected mains wiring like telephone wiring is traced. Make sure the power is off before connecting the tone generator. If live mains wiring needs to be tested, you need tools specific for that: Voltage detectors are helpful once you find your wires — they let you test whether the wires are live. You can also buy circuit and wire tracers made specifically for the purpose of locating electrical wiring behind walls and underground. These tools tend to be expensive, though.

Some instructional articles:

How to Use a Wire Tracer article gives you some basic instructions.

Deciphering wiring article has some tips on cable tracing and notes cases where tracers do not always work well.

How to find an open circuit or shorted wire the FAST easy way

Are you interested in circuit diagrams of cable tracers? Here are some pointers to those:

My Cable tracing inductive amplifier blog posting  has several circuit diagrams.

Fox and Hound cable tracer article has links to generator circuits.

Fox – Hound, Cable Tracers, Signal Tracers, Line Tracers – whatever you want to call them project page has circuit diagrams.

Cable wizard cable tracer manual has many circuit details in it.



  1. 95Tammy says:

    Hi admin, i must say you have high quality
    posts here. Your blog should go viral. You need initial traffic boost only.

    How to get it? Search for; Mertiso’s tips go viral

  2. Tomi Engdahl says:

    Knowing What’s Below: Buried Utility Location

    We humans have put an awful lot of effort into our infrastructure for the last few centuries, and even more effort into burying most of it. And with good reason — not only are above ground cables and pipes unsightly, they’re also vulnerable to damage from exposure to the elements. Some utilities, like natural gas and sanitary sewer lines, are also dangerous, or at least perceived to be so, and so end up buried. Out of sight, out of mind.

    Call Before You Dig

    By law, every public utility company in the United States must participate in a “one-call locator service.”
    Location services are paid for by the utility companies, so there’s no direct charge to the customer.

    Anyone doing any sort of excavation is required to call (or now, submit a request online) to schedule a location service to mark the intended work area. This applies to any digging
    If you’re going more than 15″ deep, you need to call, because if you cause any damage to underground services, you’re on the hook for it. If you live, of course.

    Beep, Beep, Beep

    Once a ticket is entered, a location technician will usually come mark the job site within a couple of days.

    Location techs have a wide range of tools to locate that which can’t be seen. Given that most underground facilities have some kind of metallic component — older water and sewer lines, natural gas pipes, and the copper wire in electrical or telecom cables — electromagnetic tools get the bulk of the work done.

    Detectors can be active or passive. Passive methods are usually used to locate facilities that already have an AC signal on them, like power lines or telecom cables.

    Active detection applies a current to an above-ground section of a utility line, like a water or gas meter. An AC signal is applied to the line by the transmitter, which turns it into an antenna. Utility companies sometimes even lay copper wire alongside plastic lines as an aid to active detection.
    Handheld receivers with highly directional antennas are swept over the ground to pick up the signal

  3. Tomi Engdahl says:

    MASTECH MS6818 Located underground concrete pipe at 1.4 meter depth

    Using the “MASTECH MS6818″, I located underground concrete pipe at 1.4 meter depth and at 20 meters of length. I used a wire with an copper area of 0.7mm^2 and a plastic isolation. (1.1 meter is only the entry depth, the pipe is actually located at 1.4 meter)

  4. Tomi Engdahl says:

    Tracing out Live Network Cables

    This clever trick helps you identify un-marked network outlets. A Toner and Tone-probel will not work when a network jack is connected to a live switch port in the server room (switch room). By using a simple batch file running on a laptop, you can create a beaconing effect using the swithes link lights.

  5. Tomi Engdahl says:

    How-To: Trace Live Ethernet Cables to a Switch

    Interrupting live networks is painful. But sometimes you’ve got to do work in the cable closets, server rooms, and other crowded and complex rivers of wire that are your responsibility. Does there have to be an acceptable amount of downtime for tracing and testing wires? There are a few low-impact methods for locating cable ends which are popular but disruptive. There is one newer strategy, though, which can lead you right to the cable end you seek without network disruption or disconnection. Check out the article here:

  6. Tomi Engdahl says:

    How to find an open circuit or shorted wire the FAST easy way

  7. Tomi Engdahl says:

    Harbor Freight – Cen-Tech Cable Tracker (Item#94181)

    Pass or Fail? Harbor Freight Cable Finder #94181

  8. Tomi Engdahl says:

    How to use a tone generator and probe to locate cables

    In this video we demonstrate the use of a tone generator and an inductive amplifier (probe) to locate cables.

    How to trace and track wires using a cable tracker

    Hi, this ‘how to’ video shows how to use a cable tracker tone and probe to trace and track various cables and wires.

  9. Tomi Engdahl says:

    Interesting looking commercial cable location device, product page has some cable tracing usage instructions:

    ESAMACT MS6818 Advanced Wire Tester Tracker, Multi-function Cable Detector

    working principle:

    The MS6818 cable detector includes a transmitter and a receiver. The transmitter supplies a modulated AC voltage to the corresponding cable. The AC voltage creates an electric field around the cable. The receiver is fitted with a coil. If the receiver is placed close to the corresponding electrical conductor, the flux line will Pass through the coil and into the receiver. This phenomenon is also known as a penetrating coil. A small voltage is generated in the coil, and the receiver’s electronic circuitry calculates this voltage and displays it on the display. The MS6818 is special in that the transmitted signal is digitally encoded. This ensures that the signal is clearly received by the receiver, avoiding the erroneous display caused by any interference fields such as electronic fluorescent ballasts or frequency converters.

    Application areas:

    This instrument is widely used in communication cable construction, power cable construction, construction pipeline construction, communication cable to power supply circuit and electric heating line maintenance work, is an indispensable tool for frontline construction maintenance personnel.

    Detect the laying path of cables, electrical lines, and water supply pipes buried in walls and underground.

    Detect cables that are buried in walls and underground, and open and short circuits in electrical circuits.

    Look for fuses and their fuses.

    Look for covered sockets and junction boxes.

    Look for open and short circuit faults in the electric heating circuit under the floor.

  10. Tomi Engdahl says:

    What To Do if You Mislabel a Cable in a MDU Application (The RPT-AAA)


Leave a Comment

Your email address will not be published. Required fields are marked *