Method and apparatus for the location and indication of cable splices and cable faults

1. A method of locating cable splices and cable faults, comprising:

coupling an audio frequency generator to a cable to provide a magnetic field at an audio frequency;

receiving at least two orthogonal components of the magnetic field at a receiver;

generating test values corresponding to the orthogonal components of the magnetic field along the cable route, wherein generating test values includes:

amplifying signals from a first antenna coil and a second antenna coil to produce amplified signals;

filtering the amplified signals to produce filtered signals; and

digitizing the filtered signals to produce test values;

entering the test values at a plurality of test points on the cable route to a test value memory;

determining a degree of inhomogeneity along the cable route from the test values in the test value memory; and

displaying the degree of inhomogeneity.

2. The method of claim 1 , wherein coupling the audio frequency generator to the cable includes:

connecting a first pole of the audio frequency generator to a first end of a central conductor of the cable, wherein the first pole is coupled to receive a signal output from the audio frequency generator;

connecting a second pole of the audio frequency generator to an earth ground; and

connecting a second end of the central conductor to the earth ground.

3. The method of claim 1 , wherein receiving at least two orthogonal components of the magnetic field at the receiver includes:

detecting a first component of the magnetic field with the first antenna coil; and

detecting a second component of the magnetic field with the second antenna coil oriented orthogonally to the first antenna coil.

4. The method of claim 1 , wherein entering the test values at a plurality of test points on the cable route to a test value memory includes

entering an input to a softkey at various points on the cable route to signify a test point;

storing the test values in a memory when the softkey is activated.

5. The method of claim 1 , wherein determining a degree of inhomogeneity along the cable route from the test values in the test value memory includes:

retrieving test values corresponding to various test points along the cable route that are stored in memory;

determining the variation in the two orthogonal components of the magnetic field from the test values; and

scaling the variation to form the degree of inhomogeneity.

6. The method of claim 1 , wherein displaying the degree of inhomogeneity includes:

indicating on a line trace the degree of inhomogeneity.

7. The method of claim 6 , wherein indicating on a line trace includes utilizing differing coloration to indicate the degree of inhomogeneity.

8. The method of claim 6 , wherein indicating on a line trace includes utilizing different line thicknesses to indicate the degree of inhomogeneity.

9. The method of claim 6 , wherein indicating on a line trace includes utilizing different line patterns to indicate the degree of inhomogeneity.

10. The method of claim 6 , wherein the line trace is indicated on a display of the receiver.

11. The method of claim 1 , further including overlaying a geo-information system cable route over a display to compare with the cable route.

12. A method of locating cable splices and cable faults, comprising:

coupling an audio frequency generator to a cable to provide a magnetic field at an audio frequency;

receiving at least two orthogonal components of the magnetic field at a receiver;

detecting a first component of the magnetic field with a first antenna coil;

detecting a second component of the magnetic field with a second antenna coil oriented orthogonally to the first antenna coil;

generating test values corresponding to the orthogonal components of the magnetic field along the cable route, wherein generating test values includes:

amplifying signals from the first antenna coil and the second antenna coil to produce amplified signals;

filtering the amplified signals to produce filtered signals; and

digitizing the filtered signals to produce the test values; and

entering the test values at a plurality of test points on the cable route to a test value memory;

determining a degree of inhomogeneity along the cable route from the test values in the test value memory; and

displaying the degree of inhomogeneity.

13. The method of claim 12 , wherein amplifying signals includes

determining a first gain for amplifying signals from the first antenna coil; and

determining a second gain for amplifying signals from the second antenna coil.

14. The method of claim 12 , wherein filtering the amplified signals includes

filtering the amplified signals with band pass filters that pass signals at an audio frequency matched with an output signal of a frequency generator, the frequency generator being coupled to a cable to produce the magnetic field.

15. An apparatus for finding cable splices and cable faults, comprising:

means for coupling an audio frequency generator to a cable to provide a magnetic field at an audio frequency;

means for detecting two orthogonal components of the magnetic field from the cable;

means for obtaining test values coresponding to the orthogonal components of the magnetic field at test points along the cable, wherein wherein obtaining test values includes:

amplifying signals from a first antenna coil and a second antenna coil to produce amplified signals;

filtering the amplified signals to produce filtered signals; and

digitizing the filtered signals to produce test values;

means for determining a degree of inhomogeneity in the magnetic field along the cable from the test values; and

means for displaying the degree of inhomogeneity in the magnetic field.