Abstract: A coaxial drop cable safety device is used for cable television, data and telephony applications. The device is used on buried drop cable where 60 Hz powering voltages applied to the drop cable exceed low voltage safety limits and where the drop cable is buried at depths which is less than the minimum required to meet electrical safety codes. Tap end and premise end units are connected to the drop cable. The tap end unit applies a DC voltage to the center conductor of the drop cable. A monitoring circuit in the tap end unit monitors the center conductor DC voltage to a fault from the center conductor to ground along the drop cable. The tap unit will immediately remove the powering voltage In the event of either an open or faulted condition on the center conductor along the entire length of the drop cable.

Abstract: A novel method and apparatus are used for monitoring cables for wear and damage. The system is particularly applicable to a cable system with multiple branch terminations. The cables have detection conductors, for example the metal cable jackets or other detection conductors extending the length of the conductors. These are connected electrically at the splice points in the system. At the end of each branch and at the end of the main cable, the detection conductors are each connected to a novel termination circuit. In the normal monitoring mode, the termination circuit appears as an open circuit. A DC voltage is normally applied to the detection conductors. Any current is a result of current leakage at a resistive fault along the detection conductors. The termination circuits are activated by altering the DC voltage, e.g. by reversing the polarity and increasing the magnitude of the voltage. This causes the termination circuit to perform a series of functional tests.

Abstract: The invention provides a monitor for monitoring the condition of fibre optic communication cables. The system employs one or more of the optical fibres of a cable to monitor the cable structure for damage or kinks. By using two separate laser sources and simultaneously monitoring the optical losses at two distinct and separate wavelengths, the loss signature of the monitored fibre is determined, analyzed and related to the mechanical condition of the cable structure. To monitor splice points for moisture, a special optical splice sensor unit detects any penetration of water into the splice and transmits a coded alarm signal over the monitored fibre to the optical receiver. Every splice location is assigned a unique sensor code. The optical splice sensor is driven by moisture detection cell, which forms a single cell water activated battery. Water entering the monitored splice closure wets the tape, which activates the cell.

Abstract: The invention provides a monitor for monitoring the condition of fibre optic communication cables. The system employs one or more of the optical fibres of a cable to monitor the cable structure for damage or kinks. By using two separate laser sources and simultaneously monitoring the optical losses at two distinct and separate wavelengths, the loss signature of the monitored fibre is determined, analyzed and related to the mechanical condition of the cable structure. To monitor splice points for moisture, a special optical splice sensor unit detects any penetration of water into the splice and transmits a coded alarm signal over the monitored fibre to the optical receiver. Every splice location is assigned a unique sensor code. The optical splice sensor is driven by moisture detection cell, which forms a single cell water activated battery. Water entering the monitored splice closure wets the tape, which activates the cell.

Abstract: A system is provided for monitoring a communications cable for moisture penetration. A line signal generator is connected to a metal armour layer of the cable to apply a line signal to the armour. Changes in the line signal current are monitored to detect the condition of the cable. Moisture penetration can be monitored throughout the length of the cable. The armour layer is maintained at a negative potential with respective ground. This provides an additional cathodic protection to the cable.

Abstract: A resistive fault in an electrical cable is located by applying a DC voltage to one end of the faulted cable conductor. The steady state DC voltage and current are measured at the end of the conductor where the voltage is applied. Simultaneously, the DC voltage is measured at the other end of the cable. The voltage is then reversed in polarity and the measurements repeated. Several repetitions of this procedure at each end of the conductor yields sufficient information to compute the location of the fault with reasonable accuracy. The procedure is carried out using two computer-based units, one at each end of the cable, with the two units communicating over the conductor under test.

Abstract: A fiber optic dropwire having a fiber optic transmission member between two strength members. The optical fiber has an outer coating having a higher melting point than the outer dropwire covering.

Abstract: A cable having a composite shield and armour sheath design is disclosed. The cable comprises a cable core, a sheath of corrugated laminated tape surrounding the cable core and formed by bonding a plastic coated aluminum tape to a wider steel tape with one edge of the aluminum tape registering with one edge of the steel tape, and an outer jacket of polyethylene overlying the sheath of corrugated laminated tape. The uncovered portion of the steel tape overlaps the registering edges of the laminated tape, to form a uniform unwelded overlap.

Abstract: A process and apparatus for manufacturing a cable having a composite shield and armor sheath design is disclosed. The process comprises the steps of corrugating a laminated tape formed by bonding a plastic coated aluminum tape to a wider steel tape with one edge of the aluminum tape registering with one edge of the steel tape, forming the corrugated laminated tape around a cable core with the uncovered portion of the steel tape overlapping the registering edges of the laminated tape, and extruding an outer jacket of polyethylene over the corrugated laminated tape.

Abstract: Apparatus for monitoring electrical cables for the presence of moisture within the cable along the full length of the cable and at specific points such as splices along its length comprises a pair of dielectrically separated conductors arranged along the length of the cable for communicating between a central station and remote stations along the length of the cable at the specific points to be monitored. The remote stations each include a further dielectrically separated pair of conductors for sensing moisture at the point and signals along the first pair of conductors to the central station. The central station detects moisture by an increase in current in the conductors and also detects a signal from remote stations.

Abstract: A cable assembly for detecting the ingress of water inside a cable is disclosed. The cable assembly comprises a moisture detecting tape constructed of two parallel bare conductors laminated to an insulating substrate. The tape thus constructed is applied in an open helix around the conductor core of a cable. A suitable plastic jacket is extruded over the cable core and the moisture detecting tape. A shielding tape may also be applied over the cable core and the moisture detecting tape prior to extrusion of the overall plastic jacket. The cable thus constructed with the integral moisture detecting tape is adapted for connection to a suitable sensing apparatus at one end, and should moisture enter the cable as a result of damage to same, the electrical characteristics of the detecting tape would change and such change will result in a measurable conductance between the conductors of the moisture detecting tape. The ingressing water is thus sensed prior to penetrating and compromising the cable core.