| 摘要 |
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.
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