i want to know the ckt for underground cable route locator and telecom telecom fault locator

I am working in telecom company and often deal with underground cable.I want to know easy way of tracing underground cable route locator and fault locator.Is there is any easy methods to the same or an easy ckt that can be use to trace it.


      Thanks

Hi Sanjay-Cable locators often work by injecting a high amplitude square wave into one or more conductors if the cable that is to be located, and then searching for the magnetic field given off by the cable using a search coil.Some locators use a low frequency, and in this case the search coil can be fed into an audio amplifier.  The search coil is often several hundred turns of wire around a powdered iron rod core. The output of the amplifier produces an audible tone that gets louder as you approach the route of the cable. Once you are near the cable, step off to one side of it and rotate the search coil and look for a "null".  Then move to the other side of the cable route and do the same thing. By comparing the angle at which you hear the null you can accurately "triangulate" the depth and precise location of the cable.Other systems use a higher frequency square wave, and in this case it is necessary to build a tuned circuit that only allows the search coil to hear the frequency being radiated by the cable you are searching for. The output of the tuned circuit is then fed to an amplitude detector and displayed on a meter.When you connect the sending unit of the locator to the cable, do NOT make the mistake of connecting it between two conductors within the same cable.  It's best to connect to ONE conductor of the cable, and connect the other lead of the  sending unit to a good ground connection.  If a good ground is not available, drive a spike in the ground several feet away from the cable, and if the ground is dry, pour water on the ground to improve the connection.If the cable is shielded, connect to the shield instead of one of the conductors within the cable.    When you're looking for a cut cable, walk along until the strength of the signal drops off sharply.If you're trying to find a shorted spot in a cable, walk the cable route first to locate the exact route. Then look for the point at which the signal disappears completely.If you're looking for a bad spot in the insulation of a higher voltage cable, like a power cable, the sending unit often uses a very high voltage to "break down" the fault  so it can be located.  This design requires a much more involved discussion.  -Rick

Can i get easy ckt  for cabe route tracer

The high-voltage "break down" cable tester mentioned by Rick Curl is sometimes called a thumper, because you walk along the ground above the cable listening for the thumps as the cable breaks down.
Another form of fault locator, is the Time-Domain Reflectometer, TDR. This is radar down the cable instead of through the air. A simple TDR built with a fast oscilloscope and a few TTL gates to generate the pulses can give ten-foot distance-along-the-cable resolution.
Really high-speed TDR's intended to check out microwave coax cables, may refuse to drive a power cable because the power cable, though coaxial, has excessive losses at microwave frequencies.