Apparatus for detecting imbalances in a paired line

Abstract

A device for measuring and isolating noise-creating imbalances in a paired telecommunications line has an internal circuit which comprises a balanced center tapped termination consisting of precisely equal resistor pairs. The circuit includes an adjustable sine wave burst generator which generates a low voltage longitudinal ac signal that is transmitted across the balanced pathways. A differential amplifier in the circuit measures this difference and displays it in units of noise or balance. The output of the differential amplifier is transmitted to an analog-to-digital converter. A microprocessor collects the samples in an array, and filters the results for presentation on a display. Advantageously, the microprocessor provides for adjustable and selectable bandpass filtering. Preferred bandpass filtering preferably occurs at 1 kHz, 200 KHz, 1 MHz, and 5 MHz with a preferred frequency bandpass of 3 harmonics to provide bandpass ranges of 200-600 KHz, 1-3 MHz, and 5-15 MHz, respectively, and a bandpass of 3 Hz at 1 kHz.

1 . An apparatus for measuring noise in a paired line comprising:
 a first contact engagable with a first conductor of said line;   a second contact engagable with a second conductor of said line;   measuring means in electrical communication with said first and second contacts for measuring metallic voltage signals generated by an imbalance between said first conductor and said second conductor representative of a noise in said line;   a first voltage inlet pathway across which said measuring means electrically communicates with said first contact;   a second voltage inlet pathway across which said measuring means electrically communicates with said second contact;   a first balanced pathway in electrical communication with said first contact;   a second balanced pathway in electrical communication with said second contact, said first balanced pathway substantially electrically balanced with said second balanced pathway;   an sine wave burst generator electrically connected to said first contact across said first balanced pathway and to said second contact across said second balanced pathway to provide alternating current burst of 100 or less sine wave cycles to said paired line; and   a ground pathway connected to said alternating current source, said ground pathway having ground minimizing means for substantially minimizing flow of power influence current to ground.   
   
   
       2 . The apparatus for measuring noise in a paired line of  claim 1  wherein said measuring means comprises:
 a differential amplifier for outputting the difference in metallic voltage signals generated by an imbalance between said first conductor and said second conductor;   an analog-to-digital converter for converting the analog output of the differential amplifier into a digital signal; and   a microprocessor for processing the digital signal produced by the analog-to-digital converter for producing noise results for display on a display screen.   
   
   
       3 . The apparatus for measuring noise in a paired line of  claim 2  wherein said microprocessor provides for adjustable and selectable bandpass filtering. 
   
   
       4 . The apparatus for measuring noise in a paired line of  claim 3  wherein said microprocessor provides for bandpass filtering at substantially 200 KHz, 1 MHz, and 5 MHz. 
   
   
       5 . The apparatus for measuring noise in a paired line of  claim 4  wherein said microprocessor provides for pass bands of substantially three harmonics. 
   
   
       6 . An apparatus for measuring noise in a paired line comprising:
 a first contact engagable with a first conductor of said line;   a second contact engagable with a second conductor of said line;   measuring means in electrical communication with said first and second contacts for measuring metallic voltage signals generated by an imbalance between said first conductor and said second conductor representative of a noise in said line;   a first voltage inlet pathway across which said measuring means electrically communicates with said first contact;   a second voltage inlet pathway across which said measuring means electrically communicates with said second contact;   a first balanced pathway in electrical communication with said first contact;   a second balanced pathway in electrical communication with said second contact, said first balanced pathway substantially electrically balanced with said second balanced pathway;   an sine wave burst generator electrically connected to said first contact across said first balanced pathway and to said second contact across said second balanced pathway to provide alternating current burst of a single sine wave cycle to said paired line; and   a ground pathway connected to said alternating current source, said ground pathway having ground minimizing means for substantially minimizing flow of power influence current to ground.   
   
   
       7 . The apparatus for measuring noise in a paired line of  claim 6  wherein said measuring means comprises:
 a differential amplifier for outputting the difference in metallic voltage signals generated by an imbalance between said first conductor and said second conductor;   an analog-to-digital converter for converting the analog output of the differential amplifier into a digital signal; and   a microprocessor for processing the digital signal produced by the analog-to-digital converter for producing noise results for display on a display screen.   
   
   
       8 . The apparatus for measuring noise in a paired line of  claim 7  wherein said microprocessor provides for adjustable and selectable bandpass filtering. 
   
   
       9 . The apparatus for measuring noise in a paired line of  claim 8  wherein said microprocessor provides for bandpass filtering at substantially 200 KHz, 1 MHz, and 5 MHz. 
   
   
       10 . The apparatus for measuring noise in a paired line of  claim 9  wherein said microprocessor provides for pass bands of substantially three harmonics.