Repeater monitoring and fault location

Claim 2

A repeater having a low frequency transmission path for transmission in a low frequency pass band between a first terminal and a second terminal and a high frequency transmission path for transmission in a high frequency pass band between said second terminal and said first terminal comprising first low pass filtering means, first amplifying means, and second low pass filtering means serially connected between said first and said second terminals in said low frequency transmission path, first high frequency filtering means, second amplifying means, and second high pass filtering means serially connected between said second terminal and said first terminal in said high frequency transmission path characterized in that said second low pass filtering means has a loss characteristic of a sufficiently low magnitude over a portion of said high frequency pass band to couple part of the output of said first amplifying means in said portion of said high frequency pass band to said high frequency transmission path, and said second high pass filtering means has a loss characteristic of a sufficiently low magnitude over a portion of said low frequency pass band to couple part of the output of said second amplifying means in said portion of said low frequency pass band to said low frequency transmission path.

Claim 3

A repeater as defined in claim 1 further characterized in that said first low pass filtering means has a loss characteristic of a sufficiently high magnitude over said portion of said high frequency pass band, and said first high pass filtering means has a loss characteristic of a sufficiently high magnitude over said portion of said low frequency pass band, the sum of the loss characteristics of said first and second low pass filtering means and said first and second high pass filtering means providing a predetermined loss versus frequency characteristic over said low frequency pass band and said high frequency pass band.

Claim 4

A repeater as defined in claim 2 further characterized in that oscillator means for generating a signal at a frequency between said low frequency pass band and said high frequency pass band is connected to the inputs of said first amplifying means and said second amplifying means.

Claim 5

A repeater for a coaxial cable system comprising a first transmission path for transmission in one direction in a low frequency pass band between a first and a second repeater terminal, a second transmission path for transmission in another direction in a high frequency band between said second and first repeater terminals, first low pass filtering means, first amplifying means, and second low pass filtering means serially connected in said first transmission path, said second low pass filtering means having a controlled moderate level of loss over a portion of said high frequency band to couple part of the output of said first amplifying means in said portion of said high frequency band to said second transmission path, first high pass filtering means, second amplifying means, and second high pass filtering means serially connected in said second transmission path, said second high pass filtering means having a controlled moderate level of loss over a portion of said low frequency band to couple part of the output of said second amplifying means to said first transmission path.

Claim 6

A repeater for a coaxial cable system comprising a first transmission path for transmission in one direction in a low frequency pass band between a first and a second repeater terminal, a second transmission path for transmission in another direction in a high frequency band between said second and first repeater terminals, first low pass filtering means, first amplifying means, and second low pass filtering means serially connected in said first transmission path, said second low pass filtering means having a controlled moderate level of loss over a portion of said high frequency band to couple part of the output of said first amplifying means in said portion of said high frequency band to said second transmission path, first high pass filtering means, second amplifying means, and second high pass filtering means serially connected in said second transmission path, said second high pass filtering means having a controlled moderate level of loss over a portion of said low frequency band to couple part of the output of said second amplifying means to said first transmission path.

Claim 7

A repeater as defined in claim 4 wherein said first low pass filtering means has a sufficiently high level of loss over said portion of said high frequency band, and said first high pass filtering means has a sufficiently high level of loss over said portion of said low frequency band such that the sum of the levels of loss of the said first and second low pass filtering means and said first and second high pass filtering means forms a predetermined loss versus frequency characteristic over said low frequency band and said high frequency band.

Claim 8

A repeater as defined in claim 5 further comprising oscillator means for generating a signal at a frequency between said low frequency band and said high frequency band at the inputs of said first amplifying means and said second amplifying means.

Claim 9

An arrangement for locating a faulty one of a plurality of repeaters, each repeater having first low pass filtering means, first amplifying means, and second low pass filtering means serially connected in a first transmission path between a first terminal and a second terminal for amplifying signals transmitted in a low frequency band in one direction, and first high pass filtering means, second amplifying means, and second high pass filtering means serially connected in a second transmission path between said second terminal and said first terminal for amplifying signals transmitted in a high frequency band in the opposite direction, said repeaters being spaced along a transmission line between a low frequency transmitting end and a high frequency transmitting end, said arrangement comprising means at said low frequency transmitting end to apply a first test signal at a frequency in said low frequency band to said transmission line, means at said high frequency transmitting end to apply a second test signal at a frequency in said high frequency band to said transmission line, means associated with each repeater for generating a test signal at the inputs of said first and second amplifying means at a frequency uniquely identifiable to each repeater, said first amplifying means of each repeater intermodulating said first test signal and the test signal identifiable with that repeater to generate at least one modulation component at a frequency in said high frequency band, said second amplifying means of each repeater intermodulating said second test signal and the test signal identifiable with the repeater to generate at least one modulation component at a frequency in said low frequency band, said second low pass filtering means of each repeater having a loss characteristic of a sufficiently low magnitude over a portion of said high frequency band in which the frequencies of said at least one modulation component generated by said first amplifying means of each of said plurality of repeaters lie, said second low pass filtering means of each repeater coupling the at least one modulation component generated in said portion of said high frequency band to said high frequency transmission path for transmission to said low frequency transmitting end, means at said low frequency transmitting end to detect the modulation components generated by said first amplifying means in each repeater at frequencies in said portion of said high frequency band, said second high pass filtering means of each repeater having a loss characteristic of a sufficiently low magnitude over a portion of said low frequency band in which the frequencies of said at least one modulation component generated by said second amplifying means of each of said plurality of repeaters lie, said second high pass filtering means of each repeater coupling the at least one modulation component generated in said portion of said low frequency band to said low frequency transmission path for transmission to said high frequency transmitting end, and means at said high frequency transmitting end to detect the modulation components generated by said second amplifying means in each repeater at frequencies in said portion of said low frequency band.

Claim 10

An arrangement for locating a faulty one of a plurality of repeaters, each repeater having first low pass filtering means, first amplifying means, and second low pass filtering means serially connected in a first transmission path between a first terminal and a second terminal for amplifying signals transmitted in a low frequency band in one direction, and first high pass filtering means, second amplifying means, and second high pass filtering means serially connected in a second transmission path between said second terminal and said first terminal for amplifying signals transmitted in a high frequency band in the opposite direction, said repeaters being spaced along a transmission line between a low frequency transmitting end and a high frequency transmitting end, said arrangement comprising means at said low frequency transmitting end to apply a first test signal at a frequency in said low frequency band to said transmission line, means at said high frequency transmitting end to apply a second test signal at a frequency in said high frequency band to said transmission line, means associated with each repeater for generating a test signal at the inputs of said first and second amplifying means at a frequency uniquely identifiable to each repeater, said first amplifying means of each repeater intermodulating said first test signal and the test signal identifiable with that repeater to generate at least one modulation component at a frequency in said high frequency band, said second amplifying means of each repeater intermodulating said second test signal and the test signal identifiable with the repeater to generate at least one modulation component at a frequency in said low frequency band, said second low pass filtering means of each repeater having a loss characteristic of a sufficiently low magnitude over a portion of said high frequency band in which the frequencies of said at least one modulation component generated by said first amplifying means of each of said plurality of repeaters lie, said second low pass filtering means of each repeater coupling the at least one modulation component generated in said portion of said high frequency band to said high frequency transmission path for transmission to said low frequency transmitting end, means at said low frequency transmitting end to detect the modulation components generated by said first amplifying means in each repeater at frequencies in said portion of said high frequency band, said second high pass filtering means of each repeater having a loss characteristic of a sufficiently low magnitude over a portion of said low frequency band in which the frequencies of said at least one modulation component generated by said second amplifying means of each of said plurality of repeaters lie, said second high pass filtering means of each repeater coupling the at least one modulation component generated in said portion of said low frequency band to said low frequency transmission path for transmission to said high frequency transmitting end, and means at said high frequency transmitting end to detect the modulation components generated by said second amplifying means in each repeater at frequencies in said portion of said low frequency band.

Claim 11

An arrangement as defined in claim 7 wherein the first low pass filtering means of each repeater has a loss characteristic of a sufficiently high magnitude over said portion of said high frequency band, and the first high pass filtering means of each repeater has a loss characteristic of a sufficiently high magnitude over said portion of said low frequency band, the sum of the loss characteristics of said first and second low pass filtering means and said first and second high pass filtering means of each repeater forming a predetermined loss versus frequency characteristic over said low frequency band and said high frequency band.

Claim 12

An arrangement as defined in claim 7 wherein said means associated with each repeater for generating a test signal is operative at a frequency in the cutapart region between the low frequency band and the high frequency band.

Claim 13

An arrangement for measuring the modulation performance of a repeater having first low pass filtering means, first amplifying means, and second low pass filtering means serially connected in a first transmission path between a first terminal and a second terminal for amplifying signals transmitted in a low frequency band in one direction, and first high pass filtering means, second amplifying means, and second high pass filtering means serially connected in a second transmission path between said second terminal and said first terminal for amplifying signals transmitted in a high frequency band in the opposite direction, said repeater being connected in a transmission line between a low frequency transmitting end and a high frequency transmitting end, said arrangement comprising means at said low frequency transmitting end to apply a first test signal at a frequency in said low frequency band to said transmission line, means at said high frequency transmitting end to apply a second test signal at a frequency in said high frequency band to said transmission line, means for applying a third test signal to said first and second amplifying means of said repeater, said first amplifying means intermodulating said first test signal and said third test signal to generate at least one modulation component at a frequency in said high frequency band, said second amplifying means intermodulating said second test signal and said third test signal to generate at least one modulation component at a frequency in said low frequency band, said second low pass filtering means having a loss characteristic of a sufficiently low magnitude over a portion of said frequency band in which the frequency of said at least one modulation component generated by said first amplifying means lies, said second low pass filtering means coupling the at least one modulation component generated in said portion of said high frequency band to said high frequency transmission path for transmission to said low frequency transmitting end, means at said low frequency transmitting end to detect the at least one modulation component coupled from said first amplifying means to said high frequency transmitting path, said second high pass filtering means having a loss characteristic of a sufficiently low magnitude over a portion of said high frequency band in which the frequency of said at least one modulation component generated by said second amplifying means lies, said second high pass filtering means coupling the at least one modulation component in said portion of said low frequency band to said low frequency transmission path for transmission to said high frequency transmitting end, means at said high frequency transmitting end to detect the at least one modulation component coupled from said second amplifying means to said low frequency transmission path.

Claim 14

An arrangement for measuring the modulation performance of a repeater having first low pass filtering means, first amplifying means, and second low pass filtering means serially connected in a first transmission path between a first terminal and a second terminal for amplifying signals transmitted in a low frequency band in one direction, and first high pass filtering means, second amplifying means, and second high pass filtering means serially connected in a second transmission path between said second terminal and said first terminal for amplifying signals transmitted in a high frequency band in the opposite direction, said repeater being connected in a transmission line between a low frequency transmitting end and a high frequency transmitting end, said arrangement comprising means at said low frequency transmitting end to apply a first test signal at a frequency in said low frequency band to said transmission line, means at said high frequency transmitting end to apply a second test signal at a frequency in said high frequency band to said transmission line, means for applying a third test signal to said first and second amplifying means of said repeater, said first amplifying means intermodulating said first test signal and said third test signal to generate at least one modulation component at a frequency in said high frequency band, said second amplifying means intermodulating said second test signal and said third test signal to generate at least one modulation component at a frequency in said low frequency band, said second low pass filtering means having a loss characteristic of a sufficiently low magnitude over a portion of said frequency band in which the frequency of said at least one modulation component generated by said first amplifying means lies, said second low pass filtering means coupling the at least one modulation component generated in said portion of said high frequency band to said high frequency transmission path for transmission to said low frequency transmitting end, means at said low frequency transmitting end to detect the at least one modulation component coupled from said first amplifying means to said high frequency transmitting path, said second high pass filtering means having a loss characteristic of a sufficiently low magnitude over a portion of said high frequency band in which the frequency of said at least one modulation component generated by said second amplifying means lies, said second high pass filtering means coupling the at least one modulation component in said portion of said low frequency band to said low frequency transmission path for transmission to said high frequency transmitting end, means at said high frequency transmitting end to detect the at least one modulation component coupled from said second amplifying means to said low frequency transmission path.

Claim 15

An arrangement as defined in claim 10 wherein the first low pass filtering means has a loss characteristic of a sufficiently high magnitude over said portion of said high frequency band, and the first high pass filtering means has a loss characteristic of a sufficiently high magnitude over said portion of said low frequency band, the sum of the loss characteristic of said first and second low pass filtering means and said first and second high pass filtering means forming a predetermined loss versus frequency characteristic over said low frequency band and said high frequency band.

Claim 16

An arrangement as defined in claim 11 wherein said means for applying a third test signal generates a signal at a frequency in the cutapart region between the low frequency band and the high frequency band.