TM 11-6625-648-12
t o operate the TD-204/U or TD-754/G NOR
3-6. Testing Restorers, Pulse Form
OPR-ZERO SET-READ switch to READ: this will
TD-206/G
transmit pcm pulses over the line from the attended
After communication has been established with the
stations.
i. With the TS-1323/PTM-7 METER SELECT
the TD-206/G as described in a through m below.
switch operated to DC VOLTS, note the TEST
This test is effective if the TD-206/G has com-
METER indication. The meter should indicate
pletely failed (no output and there is no traffic
approximately 10 volts for each TD-206/G between
received at the adjacent attended station). See
the TS-1323/PTM-7 and the B attended station.
paragraph 3-7a for locating a TD-206/G that is
For example, if there are 15 TD-206/G's (including
operative, but has incorrect output.
the
between
checked)
being
the
one
NOTE
TS-1323/PTM-7 and the B attended station, the
The terms A and B used in the following
meter should indicate approximately 150 volts.
i n s t r u c t i o n s have been arbitrarily
j. Operate the METER SELECT switch to DC
assigned to the attended stations (fig.
AMPS to check CX-4245/G current. The meter
3 - 3 ) .
Each TD-206/G contains two
should indicate between 7 and 10. If it indicates
slightly lower, but not zero, there may be a high-
other BA. Repeater AB transmits pcm
short c i r c u i t b e t w e e n t h e
traffic in one direction (west to east or A
TS-1323/PTM-7 and the A attended station. If a
to B) and repeater BA transmits traffic in
high-resistance short circuit is suspected, check the
the opposite direction (east to west or B
CX-4245/G as described in paragraph 3-7.
to A). The following instructions are
k. Operate the METER SELECT switch to
applicable t o repeater AB. To test
VOLT DROP to check the direct current (dc)
repeater BA, operate the DIRECTION
voltage drop across the TD-206/G. The meter in-
switch to BA (e below) and substitute B
dicates between 7 and 9 in the green zone. A nearly
for A and A for B as appropriate
full-scale deflection is an indication that the
throughout the following instructions.
TD-206/G is not receiving or is not amplifying pcm
signal.
a. Connect the TD-206/G to the TS-1323/PTM-7
l. Operate the METER SELECT switch to pcm in
to check if pcm signals are being received. If the
meter indicates zero no pcm input signal is being
c. Establish communication over the order-wire
received.
circuit with the operators at the attended stations
m. Operate the METER SELECT switch to pcm
out to check to see if pcm signals are being am-
d. Request the operator at the attended stations
plified. If meter indicates zero no pcm signal is being
to perform the following on the TD-204/G's or
transmitted.
TD-754/G's.
(1) Operate the CABLE POWER or CABLE
NOTES
CURRENT switch to ON.
If normal indications are obtained in k,
l, and m above, and if the TD-206/G
(2) Operate the NOR OPR-ZERO SETREAD
switch to ZERO SET.
being tested and the CX-4245/G and
e. Operate the TS-1323/PTM-7 DIRECTION
TD-206/G's preceding it are apparently
switch to AB.
operating satisfactorily, the trouble is
f. Operate
the
TS-1323/PTM-7
METER
between the TS-1323/PTM-7 and the B
SELECT switch to DC VOLTS to check cable
attended station.
voltage drop. The meter should indicate ap-
If an abnormal meter indication is
proximately 14 volts for each TD-206/G between
obtained in k and m above, the TD-206/G
the TS-1323/PTM-7 and the B attended point
being tested is probable defective, and
(including the one being checked). For example, if
s h o u l d be replaced. Insert the new
there are 15 TD-206/G's (including the one being
TD-206/G and repeat the above
checked) between the TS-1323/PTM-7 and the B
procedure.
attended station, the meter should indicate ap-
If an abnormal meter indication is
proximately 210 volts (14 volts per TD-206/G).
obtained in k, l, and m above, the trouble
g. Momentarily o p e r a t e the ORDERWIRE
is between the TS-1323/PTM-7 and the
switch to SIG to signal the attending operators.
A attended station.
h. Request the operators of the attended stations
3-10
Change 5