EFJohnson 3000 SERIES - Manual (Page 124)

TELEPHONE INTERFACE MODULE (TIM)
14-14
4. Set the Transmission Test Set to generate 395 Hz. If
non-standard dial tone frequencies are used, use the
frequency measured in Step 14.
5. Adjust the generator until J11 is the same level as
measured in Step 14.
6. Monitor J11, decrease the output of the Transmis-
sion Test Set until the level at J11 is 10 dB below the
level in Step 17.
7. Adjust R210 on the personality card for
-6 dBm,
±
1 dB at EP222.
8. Adjust R257 for a peak reading at U203, pin 7.
9. Connect an oscilloscope or DC voltmeter to EP225.
Adjust R274 until EP225 is high, slowly adjust
R274 until EP225 just goes low.
10.Remove the Test Set from EQU jack.
11. Set S5 for 0 and reset the card by pressing S2. A 2
should be displayed on the front 7-segment display.
14.7.3 OUTPUT HYBRID ADJUST
1. Insert the lineman's set into the MON jack of J1 and
dial the Silent telephone number. If a silent number
is unavailable, call a nearby phone where the
mouthpiece can be removed or covered to obtain a
quiet termination.
2. Set S5 for Test 1 (section 1 open, 2, 3, 4 closed).
3. Reset the module and remove the lineman's set.
4. Connect the Transmission Test Set to J12 and adjust
R44 for a level -4 dB plus the level recorded in
Section 14.7.1, Step 6. There is 8 dB loss through
the hybrid.
Example 1:
Assume the CO maximum level is 0 dBm and
that the Test Tone is sent at this level (0 dBm).
Assume the level measured in Section 14.7.1, Step 6 is
-7 dBm. This means there is 7 dB of line loss. The
level at J12 should be set to 0 dBm as maximum level
minus 12 dB for the Switch Alignment Tone relative
to maximum level plus 8 dB for hybrid loss plus 7 dB
for line loss for an Absolute Level of +3 dBm.
J12 = 0 dBm-12 dB+8 dB+7 dB = +3 dBm
Example 2:
Assume a PBX maximum level is sent at a
-10 dB relative level or an absolute level of -12 dB.
Assume the level measured in Section 14.7.1, Step 6 is
-15 dBm. This means there is 3 dB of line loss. The
level at J12 should be set to -2 dBm as maximum level
minus 12 dB for the Switch Alignment Tone relative
to maximum level plus 8 dB for hybrid loss plus 3 dB
for line loss for an Absolute Level of +3 dBm.
J12 = -2 dBm-12 dB+8 dB+3 dB = -3 dBm
5. Adjust Hybrid Balance by monitoring J11 with the
Transmission Test Set.
a. Switch in/out S201-S202 and adjust R261-R262
for a minimum level.
b. Switch S201-S202 in or out until little change or
degradation is noted.
c. Tune R261-R262 for minimum, then switch
S201-S202 for minimum and again tune R261-
R262 for minimum.
d. This process should be repeated several times.
The level should be -20 dB minimum (typically
≈
30 dB) from the level recorded in Step 7.
5. Set S5 for Test 3, (sections 1, 2 open, 3, 4 closed).
6. Connect the Transmission Test Set to EP221 and
adjust R206 for -12 dBm.
7. Set S5 for normal operation (all sections closed).
8. Remove the card from the extender card and insert
the card back into the appropriate slot. The card
displays a "2" in the 7-segment display.
9. To display digits dialed on the system, to or from the
TIM and SNM on the Alarm Display, select the
following: