Operation
Section 1
Page 56
Noise
RED to RING
BLACK to TIP
GREEN to GROUNDED SHIELD
Hookup:
R
B
G
About the Noise Test
Use the
NOISE
key to dial to a quiet line and measure
unwanted signal in subscriber loops. The unit displays
noise metallic, power influence (noise to ground), and
calculated balance. Some units are equipped to measure
longitudinal balance* with the Noise routine.
The 900/900M Series test sets can also measure noise,
power influence and calculate balance on a vacant pair.
The far end should be terminated with a 600-ohm balance
termination for this process.
Note: If your test set is equipped with an optional backlight,
you must turn it off for the noise test. The activated backlight
affects the line noise test results.
Caution
If hazardous voltage warnings are displayed when the test set is
switched on or reset (or at any time during the testing
procedure) follow standard procedures for de-energizing and
discharging cables.
*Longitudinal balance test in accordance with ANSI/IEEE
standard 455–1985.