Locating system for a cable system having a backbone and branch cables defining multiple terminations

A method comprising:

• providing a backbone cable with inner and outer ends and a signal conductor from the inner end to the outer end;
• providing a plurality of branch cables with respective inner and outer ends and with the inner ends spliced to the backbone cable, each of the branch cables having a signal conductor spliced at the inner end of the branch cable to the signal conductor of the backbone cable;
• applying an electrical signal to the signal conductor at the inner end of the backbone cable, the electrical signal defining an alternating tone current at a tone frequency;
• providing resistive terminations at the outer end of the backbone cable and at the outer end of each branch cable,
• providing a signal return path;
• discharging the tone current at each termination to the signal return path;
• and maintaining substantially constant a maximum amplitude of the discharged electrical signal current at each termination.

A cable installation comprising:

• a backbone cable;
• a plurality of branch cables;
• splices coupling the branch cables to the backbone cable;
• and tone conductors along the backbone and branch cables, the tone conductors being connected at the splices;
• and a cable locating system for locating the backbone cable and the branch cables, the system comprising:
• a tone source connected to the tone conductor of the backbone cable at an inner end of the backbone cable for applying a current signal to the tone conductors of the backbone cable and branch cables defining an alternating tone current at a tone frequency;
• and a plurality of terminations each connected to a respective one of the tone conductors at ends thereof remote from the tone source and the splices;
• each termination defining a load impedance between the respective tone conductor and a tone signal return path for discharge of the current signal from the tone conductor;
• and each termination being arranged to limit an amplitude of the discharged current to a maximum value which is sufficient for cable location, thus ensuring that branches furthest from the tone source have adequate current for location purposes;
• and the terminations being arranged such that the maximum value of the discharged current is the same at each termination.

A method comprising:

• providing a backbone cable;
• providing a plurality of branch cables;
• providing splices coupling the branch cables to the backbone cable;
• providing tone conductors along the backbone and branch cables, the tone conductors being connected at the splices,
• providing a tone source connected to the tone conductor of the backbone cable at an inner end of the backbone cable for applying a current signal to the tone conductors of the backbone cable and branch cables defining an alternating tone current at a tone frequency;
• and providing a plurality of terminations each connected to a respective one of the tone conductors at ends thereof remote from the tone source and the splices;
• arranging each termination to define a load impedance between the respective tone conductor and a tone signal return path for discharge of the current signal from the tone conductor;
• at each termination limiting an amplitude of the discharged current to a maximum value which is sufficient for cable location, thus ensuring that branches furthest from the tone source have adequate current for location purposes;
• and arranging the terminations such that the maximum value of the discharged current is the same at each termination.