| Tone
Source |
| The
test probe requires a tone source
in the range of 500 to 1000 hertz
that can be applied at the CO or locally.
Performance of the test probe is better
with a modulated tone. |
 |
|
NOTE:
Whenever possible, disconnect the
conductors under test from the CO
or customer's station equipment to
prevent circuit equipment and customer
interference from the locally applied
tone source. Where toll equipment
is involved, apply the tone directly
to the cable pair or to the vertical
side of the main distributing frame
(MDF) with the heat coils (or protectors)
removed when possible. Failure to
do any of the above substantially
reduces the volume of the tone. |
|
| Connect
the tone source to a metallic circuit,
either across a cable pair or split-cable
pairs. Connecting the tone to ground
dissipates the signal causing conductor
identification difficulty. |
|
| When
using the test probe, do not touch
the metal tip with the hand or finger,
or a reduction in the volume of tone
heard in the Butt Set or speaker will
result (the human body "loads
down" the circuit). |
| Tone
Probe Operation Check |
| Before
using the test probe, check it for
operation. Connect one of the hand
test telephone (butt set) spring clips
to either contact tab (the "ears"),
set the hand test telephone set to
the TALK position, and place the receiver
to your ear. Connect the other butt
set spring clip to the other "ear"
(needle point of the spring clip should
fit into the hole on the "ear").
A battery "click" should
be heard in the butt set receiver.
Where available, the condition of
the test probe can be determined further
by holding it near a source of induced
noise such as fluorescent lamps, motors,
dial tone, computer or TV screens,
etc. Although the probe is normally
used with the butt set switch in the
TALK position, it also functions in
the MONITOR position, but at a reduced
volume. At times, this reduced volume
may make it easier to identify the
proper cable pair. |
| CAUTION:
The test probe need only be held near
a noise source to check operation. |
| NEVER
touch the metal tip to exposed power
sources such as electrical outlets.
|
| Anytime
the probe is not in use, remove the
butt set clips from the ears to prevent
battery drain. |
| CAUTION:
Never connect a test probe across
a working line with the switch of
the butt set in the MONITOR position.
The probe may be damaged. |
| Identifying
Wiring or Cabling |
| With
the tone connected, identify a specific
line pair from among a large number
of pairs by inserting the test probe
tip into groupsof wires until tone
is heard. In multi-binder cables,
insert the test probe tip into groups
of wires comprising the binder group
until the tone is heard. Once generally
located, touch the individual conductors
with the probe tip until the tone
is distinctly heard (loudest) indicating
the conductors under test. |
|
| As
a final test, place the probe tip
parallel to and against the conductors
being identified. Tone should be heard,
indicating the conductors under test.
|
| Locating
Opens |
| Locate
opens with the test probe in a manner
similar to identifying conductor pairs.
With the tone applied and the conductor
pair identified, move the test probe
along the pair until a definite lessening
of the tone is heard, which indicates
the open has been passed. If only
one conductor of a pair is believed
open, any slight drop in the tone
volume is an indication that the open
has been passed. The tone may carry
past the open on the good conductor. |
