MEASURE IMPULSE NOISE
-1
Chart 1004-l
MEASURE IMPULSE NOISE
STEP PROCEDURE
1
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.
2
Using Figure 1004-L Determine that for a given loop loss and noise threshold, the impulse
noise counts per
15
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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