TB11-6625-596-12/1
Table 7. Norm for Telephone Efficiency Send-Electrical Test
TEST CONDITION switch
TEST CONDITION switch
in TEL LINE position
in ART REC position
Telephone unit
Notes
VALUE control
Meter limits
VALUE control
Meter limits
C
C
TA-1/PT .............
6 .........................
45-55 ...............
0..........................
25-35 ..................
Use 1 cable C, 2 cable E's.
TA-105A/FTC......
13 ......................
45-55 ...............
8..........................
45-55 ..................
Use 3 cable E's.
TA-236/FT...........
13 ......................
40-60 ...............
8..........................
45-65 ..................
Use 3 cable E's.
TA-264/PT ..........
13 .......................
45-55 ...............
11........................
45-60 ..................
Install batteries. Be sure cradle
switch is locked down. Use 1
cable C, 2 cables E's
f. Measurement of Telephone Efficiency Receive
Electrical Test.
(3) The meter should read midscale. If the
meter does not indicate midscale, adjust the METER
SENSITIVITY CALIBRATE control for a midscale
reading.
(2) Set the front panel controls as follows:
(4) Remove the receiver from the telephone
handset.
Control
Setting
(5) Connect the front panel ART REC
BATTERY switch ................................ LB for local battery tele-
terminals to the telephone handset wires which have
phones, CB-CBS for all
been removed from the receiver.
others.
(6) Connect front panel TEL LINE terminals LI
TEST CONDITION switch .................. ART REC.
and L2 to the corresponding terminals on the telephone
MICROPHONE LOAD switch ............. OFF.
set.
RECEIVER LOAD switch ................... OFF.
(7) Press the LONG LINE button. The meter
MICROPHONE CURRENT control .... OFF.
should read within the meter limits indicated in table 8.
TELEPHONE EFFICIENCY-
RECEIVE button ............................ Depressed.
VALUE C control ................................ See table 8.
Table 8. Norms for Telephone Efficiency Receive-All Electrical Test
Telephone unit
VALUE control
Meter
Notes
limits
TA-1/PT
6
45-55
Use 1 cable C, 1 cable E.
TA-105A/FTC
2
45-55
Use 2 cable E's.
TA-236/FT
2
45-60
Use 2 cable E's.
TA-264/PT
6
45-55
Install batteries. Be sure cradle witch is locked down. Use 1 cable C,
1 cable E.
g. Telephone Efficiency Send-Acoustical Test.
SENSITIVITY CALIBRATE control for a midscale
reading.
(2) Set the front panel controls as follows:
(4) Insert the telephone handset in the
coupler. The receiver should fit squarely over the test
Control
Setting
microphone.
BATTERY switch ............................... LB for local battery
loudspeaker. The test loudspeaker should be about in
telephone CBCBS for
its midposition for this test.
all others.
(5) Connect front panel TEL LINE terminals LI
TEST CONDITION switch .................. COUPLER.
and L2 to the corresponding terminals on the telephone
NOISE GENERATOR witch ............... DRIVER.
MICROPHONE LOAD switch ............. OFF.
set.
RECEIVER LOAD switch ................... OFF.
(6) Press the LONG LINE button. The meter
MICROPHONE CURRENT control ..... OFF.
should read within meter limits indicated in table 9.
TELEPHONE EFFICIENCY-SEND
(7) Set the TEST OONDITION switch to TEL
button .............................................. Depressed .
LINE.
LEVEL A and B control ...................... See table 9.
(8) Set the VALUE control C to value given in
VALUE C control................................. See table 9 (Test
CONDITION switch at
(9) Press the LONG LINE button. The meter
COUPLER).
should read within meter limits indicated in table 9.
NOTE
(3) The meter should read midscale. If the
Tape handset switch to ON while testing.
meter does not read midscale, adjust the METER
8