Modified duobinary regenerative repeater testing arrangement
AssigneeGTE Automatic Electric Laboratories Incorporated
InventorAdam Lender
Life of this patent
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Abstract
Modified duobinary regenerative repeaters are tested in situ by means of a pulse pattern generator connected to the repeatered span line, a plurality of audio filters, one at each repeater site, a return transmission path and a measuring device for determining the character of the signal output from a selected repeater.
Claims10
An arrangement for remotely testing, from a test location, the transmission characteristics of modified duobinary regenerative repeaters in situ in a repeatered line, said remote testing arrangement comprising:
- means for generating a modified duobinary pulse test pattern composed of repetitious patterns of pulses, each said test pattern characterized by the presence of two pulses of one state followed by two pulses of the opposite state, which is followed by two pulses of said one state, said generating means comprising:
- means to vary the repetition rate of said test patterns, thereby changing the pulse density, and means to invert the polarity of the pulses in the pattern at any one of a number of predetermined rates, thereby generating one of a number of predetermined audio frequencies, one said predetermined audio frequency for each repeater location, said generating means having an output;
- means for transmitting the predetermined audio frequency from the output of a repeater to said test location, said transmitting means having an output;
- means for measuring the amplitude of the predetermined audio frequency, said measuring means having an input;
- and
- means for selectively and simultaneously connecting the output of said pulse pattern generator to said repeatered line and said transmitting means to the input of said measuring means, and for selectively and simultaneously connecting the output of said pulse pattern generator to the input of said measuring means and disconnecting said transmitting means therefrom.
In an arrangement for testing the transmission characteristics of modified duobinary regenerative repeaters in situ in a repeatered line, means to generate a modified duobinary pulse test pattern which comprises:
- timing means;
- counting means having an input connected to the timing means, having a programmable second input, and having a plurality of outputs;
- alternating means having an input connected to said timing means and having a first output providing a first binary signal at any one of a number of predetermined rates, and having a second output providing a second binary signal which is of the opposite phase from said first binary signal;
- logic means having a first input connected to an output of said counting means, having a second input connected to the first output of said alternating means and having a third input connected to the second output of said alternating means, and having an output;
- and
- coupling means having an input connected to the output of said logic means and having an output.
Dependencies are inferred from the claim text.