50
Sidekick
®
Plus Test Set
Measuring Circuit Noise
and Power Influence (PI)
The circuit noise and power influence measurements
are performed on the same display.
Power Influence
The power influence measurement specifically
identifies electromagnetic interferences (EMI) from
external sources (mainly power lines). When this test
is activated, the Sidekick
®
Plus test set shorts ring and
tip while simultaneously measuring the noise to ground.
Circuit Noise
Circuit noise on cable pairs is generated internally
by pair imbalances or externally by C.O. equipment,
subscriber equipment, or electromagnetic interfer-
ence (EMI) equipment (radio transmitters, generators,
transformers, etc.).
Normally, a poor ground or sheath on the cable pair or
the external equipment allows noise to “leak” onto the
cable pair.
Balance
Balance is a longitudinal measurement calculated by
subtracting the circuit noise measurement from the
power influence measurement. Balance represents the
overall quality of those measurements.
When the power influence and circuit noise mea-
surements are complete, the test set automatically
calculates and displays the balance.
The Sidekick
®
Plus test set measures the amount of
circuit noise present across tip and ring. The procedure
is as follows:
1. Connect the black lead to tip, the red lead to ring,
and the green lead to ground.
2. Move the rotary knob to the NOISE/PI position.
3. Press
F3 Dial
to dial a quiet line termination. The
“Power Influence” reading appears on the screen.
F2 Phone Book
may be selected to choose a
number in the stored phone book. Frequently used
numbers can be saved under this menu.
