Extending the capability of a fault locate line

Claim 1

In a cable transmission system, a fault locate system comprisinG: a fault locate line having two conductors extending from a first to a second attended repeater station, a first and a second section of said line being joined by a crossover to reverse the polarity of the power of the conductors of said line, means for transmitting information between said attended repeater stations comprising a transmission network having several serially unattended repeater stations located along the transmission path, each of said unattended repeater stations being connected through filtering means to a fault locate amplifier connected to said line, a first group of said amplifiers being connected to said first section, a second group of said amplifiers being connected to said second section, each of said amplifiers being activated in response to a predetermined polarity of the power on said line, said attended repeater stations each having testing means connected to said network and capable of generating a group of different test signals, each one of said filtering means being individually responsive to a different test signal, means for detecting the group of the different returning test signals being connected to said line at the attended repeater station generating said test signals for evaluating the operation of the individual unattended repeater stations to locate a faulty repeater along said path, and means for reversing the polarity of the power connected to said line for selectively powering said first or second group of said amplifiers such that each of said groups can be tested individually by said testing means.