User's Manual

MEASURE IMPULSE NOISE

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Chart 1004-l

MEASURE IMPULSE NOISE

STEP PROCEDURE

Measure impulse noise on selected lines during busy hours. Use an NE-58B Noise

measurement set, or equivalent.

Note: The termination and weighting filter required are 135 Ohm and 100

kHz

respectively. and the blanking interval 25 microseconds.

Using Figure 1004-L Determine that for a given loop loss and noise threshold, the impulse

noise counts per

minutes are below the corresponding curve.

Note: The values in Figure 1004-l were derived assuming the counter has a count

rate of 512 pulses per second.

Note: Due to the inaccuracy of the Noise Measuring Set, it is possible that

additional errors may occur during the blanking interval and the reading will

consequently be lower than actual.

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