Bell System Practices Plant 33 ASR Manual page 13

(
(
ISS 1, SECTION 580-301 -200
35 ROTR OPTION CONNECTIONS
WIRING FIELD
OPTION
DESIGNATION
C
@-::-@
31Y
A REMOVE YEL WIRE
ON@) AND
CONNECT TO
@.
REMOVE BR WIRE
ON@) AND
CONNECT TO @.
REMOVE@-@
4
MOVE YEL WIRE
B
FROM@) TO@.
MOVE BR WIRE
FROM @TO@).
4. PREOPERATIVE ADJUSTMENTS AND TESTS -
DATA SET 108A-TYPE
4.01
Screw switch D (Fig. 7) on Data Set
108A-type will have been closed to pro-
vide maximum sensitivity (maximum gain of the
receive buffer amplifier) during manufacturing
tests. The gain of the amplifier may be reduced
in two 4-dB steps and should be adjusted to fit
the requirements of each installation. Table A
shows the reduction in gain for each screw set-
ting. The screw switches should be set accord-
ing to the service order and/or worksheet.
HYBRID NETWORK STRAPPING
4.02
Strapping of the hybrid is determined by
the loop impedance of the facility. The
loop impedance should be shown on the service
order and/or circuit layout record card. Table B
K
CONNECTOR
REMARKS
MST 1 (WH-OR WIRE)
USE "A" CONNECTOR
MST 1 (WH-OR WIRE)
USE "K" CONNECTOR
shows typical loop impedance if the cable make--up
is known. Select the proper facility make- up un-
der the TYPICAL LOOP F AGILITY column.
Find the typical loop impedance at 2125 Hz cor-
responding to the Data Set 108A-type operation.
When the impedance is found, ref er to Table C
for the strapping required for the optimum trans-
hybrid balance. Set screw switch C and strap
E-F as indicated in the table. Refer to Fig. 7
for the location of screw switches and the strap.
4.03
Upon completion of hybrid network strap-
ing, plug Data Set 108A-type into DAS
820Bl or 820B2.
DATA SET LEVEL ADJUSTMENT
4.04
Connect terminals
+
and - of Portable
Station Test Set TTS-28 to TP 1 and TP 2
of the data set (Fig. 7). Set FUNCTION switch
of TTS-28 to DBM 900n TERM
O
position.
Page 13