Tellabs 9908B User manual

99088 Active Prescription Equalizer Subassembly
•il!itellabs
technical manual
76-839908B
rev A
practice
section 839908B
©Tellabs, Inc., 1 February 1986
all rights reserved, printed in USA
1. description and application
1.01 The 9908B Active Prescription Equalizer
subassembly (figure
1) provides active slope-type or
bump-type amplitude equalization for nonloaded or
loaded cable facilities. This equalization is equiva-
lent
to that provided by the Western Electric 309B
Prescription Equalizer and is adjusted via prescrip-
tion-set slope, height, and bandwidth switches. The
9908B subassembly plugs onto avariety of Tellabs
modules.
102 This practice section is reissued to cover the
Issue 3version of the 9908B SUbassembly (Tellabs
part number 8399088). The Issue 3 9908B is
functionally identical to its Issue 2
counterpart but
includes abypass switch
that allows its equalization
circuitry to be electrically bypassed without remov-
ing the subassembly from its
host module.
Note: The Issue 3version of the 99088 cannot be
used on Tellabs Issue 1441X and 442X-series Data
Station Termination (DST)
modules (Tellabs part
numbers 81441X and 81442X). However, the Issue
3
99088 can be used on the Issue 2versions of the
Tellabs 4416X
and 4418X DST's (Tellabs part num-
bers
824416X and 824418X).
1.03 The 9908B subassembly is generally used
to post-equalize the receive channel of a 4wire
transmission path. It provides low-end slope equali-
zation
down to 404Hz and high-end bump equaliza-
tion centered
at 3250Hz. Degree of slope, height of
bump, and affected bandwidth are controlled by the
subassembly's two DIP switches. If, in a particular
application or during testing, no equalization is
desired,
the 9908B can be excluded from the circuit
(electrically bypassed) by means of aswitch option
on the subassembly. Removal of the subassembly
from its host module is not required.
104 Figures 2and 3 show typical response
curves for the 9908B equalizer in the slope mode.
Figure 2shows the
curves for nonloaded cable,
while figure 3shows
the curves for loaded cable.
For comparison purposes, all
frequency-response
curves in figures 2and 3are drawn with the same
OdB-gain reference
point (1004Hz). Actually, all of
these curves except for those for aSLOPE switch
setting of 0are raised above
the OdB level at
1004Hz by as much as 11.4dB. The exact amount
by which a particular curve is raised depends upon figure 3. Typical response
curves for 99088 in slope mode,
loaded cable
14
~1&
8
6
4 I SLOPE
SETTINGS
FREQUENCY (Hz)
FREQUENCY (Hz)
4
~2
figure 2. Typical response curves for 9908 in slope mode,
non loaded cable
the SLOPE and LlNL (Ioaded/nonloaded) switch set-
tings selected. These amounts are listed in table 1
figure 1. 99088 Active Prescription Equalizer
subassembly
-4
iii"
"0
- I e----
zo ............ ~ 1_1
C(
Cl
page 1
page 3
page 3
page 4
page 4
contents
section 1description and application
section 2installation
section 3
circuit description
section 4 specifications
section 5testing and troubleshooting
•
•
page 1

practice section 839908B
figure 4. Typical response curves for 9908B in bump
mode, BW switch = 14
6
14
10
~
HTSETTINGS
FREQUENCY (Hz)
2
8
6
10
l..JNL
SLOPE
(Ioaded/nonloaded)
switch switch
setting
setting
L NL
0O.OdS O.OdS
(slope
disabled)
11.4 0.4
22.6 0.9
33.7 1.4
44.7 1.8
55.5 2.3
66.3 2.8
77.2
3.4
87.8 3.7
9
8.4
4.2
10 9.0
4.6
11
9.5
5.0
12 10.0
5.4
13
10.5
5.8
14
11.0
6.2
15
11.4
6.6
table 1. Equalized gain (in dB) at 1004Hz in slope mode
HT SETTINGS
figure 5. Typical response curves for 99088 in bump
mode, BWswitch =3
the SLOPE and LlNL (Ioaded/nonloaded) switch set-
tings selected. These amounts are listed in table 1.
1.05 Figures 4and 5 show typical response
curves for the 9908B equalizer in the bump mode.
Figure 4
shows the curves representing various
height settings versus a wide bandwidth setting,
while figure 5
shows the curves representing
various
height settings versus a narrow bandwidth
setting. For
comparison purposes, all frequency re-
sponse
curves in figures 4and 5are drawn with the
same OdB-gain reference point (1004Hz). Actually,
all of
these curves except those with an HT switch
setting of 1 or a and/or with a BW switch setting of
5
or less are raised above the OdB level by as much
as 3.9dB. The exact
amount by which a particular
curve is raised depends upon the HT and BW
switch settings selected. These amounts are listed
in table
2.
1°l
8
6
m
~
z4
;;(
t'
2
00
-2
1000 2000 3000
FREQUENCY (Hz)
14
4000
HT switch
BW switch setting**
setting*
6789
10
11
12
13 14 15
2O.OdS O.odS O.OdS O.OdS O.OdS O.OdS O.OdS 0.1dS 0.1dS
0.2dS
3
0.0
0.0 0.0 0.0 0.0 0.0 0.1 0.1 0.1
0.3
4
0.0
0.0 0.0 0.0 0.0
0.1 0.1
0.1
0.2 0.4
5
0.0 0.0 0.0
0.1 0.1 0.1 0.1 0.2 0.3 0.5
60.0
0.0 0.1 0.1 0.1
0.1
0.2 0.2 0.4 0.7
7
0.0 0.1 0.1 0.1
0.1 0.2 0.2 0.3 0.5 0.9
8
0.0
0.1
0.1 0.1 0.2 0.2 0.3 0.4 07
1.2
9
0.0 0.1
0.1 0.2 0.2 0.3 0.4 0.5 0.8 1.5
10
0.1 0.1
0.2 0.2 0.2 0.3
0.4 0.6 1.0 1.7
11
0.1 0.1
0.2 0.2 0.3 0.4 0.5 0.7 1.2 2.0
12
0.1 0.1 0.2 0.3 0.3
0.4 0.6 09
1.4 2.4
13 0.1
0.2 0.3 0.3 0.4 0.6 0.8 1.1 17
2.8
14 0.1
0.2 0.3 0.4 0.5 0.7 0.9 1.3 2.0 3.3
15 0.2 0.3 0.4 0.5 0.7 0.9 1.2 1.7 2.5 3.9
*HT switch position 0 disables bump function. HT switch position 1 introduces O.ldB of gain or less at 1004Hz.
**BW switch positions 0 through 5 introduce 0.1 dB of gain or less at 1004Hz for all HT settings.
table 2. Equalized gain (in dB) re 1004Hz in bump mode
page 2

practice section 839908B
figure 6. 99088 switch locations
1.06 Input power is supplied to the 99088 sub-
assembly via the
host module. The 99088 adds a
nominal 2mA (maximum)
to the host module's
current consumption, with 1.5mA maximum being
typical in most applications.
1.07 The
99088 makes electrical and physical
connection to its host
module via afive-pin connec-
tor (male on the 99088, female on the host module).
The subassembly is
further secured to the module
by
two standoff posts and screws.
2. installation
inspection
2.01 The 99088 Active Prescription Equalizer
subassembly should be visually inspected upon
arrival
to find any damage incurred during ship-
ment. If
damage is noted, aclaim should immedi-
ately be filed with
the carrier. If stored, the
subassembly should be visually inspected again
prior
to installation.
mounting
2.02 The 99088 makes physical and electrical
connection
to its host module via five-pin male con-
nector P1 on the subassembly and afive-pin female
receptacle on the
host module. Two standoff posts
and screws
further secure the subassembly to the
host module.
option selection
2.03 The 99088 contains one option switch, S3, a
two-position miniature slide switch
whose location
on the subassembly is shown in figure
6. Depend-
ing upon the
setting of this switch, the 99088's
equalization circuitry is either inserted into the host
module's transmission path or electrically bypassed,
as desired. Set S3 as follows:
•
To include the 99088 equalizer in the host mod-
ule's transmission path,
set S3 to the EQ
(equalization) position. Then align the sub-
assembly as directed below.
•
To exclude the 99088 equalizer from the host
module's transmission path when no equaliza-
tion is desired,
set S3 to the BYP (bypass)
position.
83-99088
:1
152
~ EQ
NmD 53
;;;; iBYP P1
~ J~ E9 iii; 1
~ :.:
..- .•.
'.'
:.:5
. __ .
110
1'
.... ~
N 0
511~ 41
E9
figure 6. Switch S1 is afive-position DIP switch that
conditions the subassembly for use with nonloaded
or loaded cable (SLOPE
NL position) and also con-
trols the
degree of slope for the equalization
introduced (SLOPE 1, 2, 4, and 8positions). Switch
S2 is an eight-position DIP switch
that controls the
height of bump of the equalization introduced (HT 1,
2, 4, and 8positions) and also determines the
bandwidth affected by that equalization (BW 1, 2, 4,
and 8positions). For each equalization parameter
(slope, height, and bandwidth),
the 1, 2, 4, and 8
switch positions are cumulative:
the selected
SLOPE, HT, or BW equalization setting is the sum of
the respective 1, 2, 4, and 8DIP-switch positions set
to ON. Thus, for each equalization parameter, aset-
ting
of 0 to 15 is possible.
Note: In the alignment procedures that follow, the
ON setting for the SLOPE, HT, and BW DIP
switches is
toward the arrowhead on the switch
body. The
OFF setting is away from the arrowhead.
alignment procedure
2.05 Because the 99088 is functionally equiva-
lent
to the Western Electric 3098 Prescription
Equalizer,
alignment procedures for the 3098 also
can be used
for the 99088. Prescription alignment
procedures can be found in 8ell System Practice
(8SP)
section 332-912-232, while non-prescription
alignment procedures are contained in 8SP section
332-912-234.
2.06 If
neither of the above practice sections is
available,
satisfactory results can often be obtained
by aligning the 99088 as follows:
A. Initially set the 99088's BW (bandwidth), HT
(height), and SLOPE DIP switches as follows:
•For 7kilofeet
or less of nonloaded cable:
SLOPE NL to ON, BW for 0, HT for 0, SLOPE
for O.
•For more than 7 kilofeet of nonloaded cable:
SLOPE NL to ON, BW for 14, HT for 3, SLOPE
for O.
•For loaded (H88) cable: SLOPE NL to OFF,
BW for 6, HTfor 2, SLOPE for O.
8. Make a frequency run in accordance with local
practice, and
optimize the 99088 switch set-
tings as follows:
•
To reduce loss above 1800Hz, adjust the HT
DIP switch for a higher value.
•
To reduce loss below 1800Hz, adjust the
SLOPE DIP switch for a higher value.
•
Further adjustment of the BW DIP switch is
usually unnecessary.
3. circuit description
3.01 The 99088 Active Prescription Equalizer
Subassembly is functionally identical to the West-
ern Electric
3098 Prescription equalizer. The
amount of equalization introduced into the receive
channel is controlled by the SLOPE, HT (height), and
BW (bandwidth) DIP switches. An option switch on
alignment overview the 99088 allows its equalization circuitry to be
2.04 The
99088 contains two alignment electrically bypassed without removing the sub-
switches,
S1 and S2, whose locations are shown in assembly from the host module.
page3

practice section 839908B
Equivalent to those of the Western Electric 309B
Prescription Equalizer.
5. testing and troubleshooting
5.01 The testing guide checklist in this section
may be used
to assist in the installation, testing, or
troubleshooting of the 9908B Active Prescription
Equalizer Subassembly. The
checklist is intended
as an aid in the localization of trouble to aspecific
subassembly. If asubassembly is
suspected of
being defective, a new one should be substituted
and the test conducted again. If the substitute sub-
assembly
operates correctly, the original sub-
assembly should be considered defective
and
returned to Tellabs for repair or replacement as
directed below.
We strongly recommend that no
internal (component-level) testing
or repairs be
attempted on the 9908B subassembly. Unauthor-
ized testing or repairs may void the
9908B's
warranty. Also, if the subassembly is part of aregis-
tered system, unauthorized repairs will result in
noncompliance with Part
68 of the FCC Rules and
Regulations.
Note: Warranty service does not include removal of
permanent customer markings on Tellabs products,
although an
attempt will be made to do so. If aprod-
uct must be marked defective, we recommend that
it be done on apiece of tape or on aremovable
stick-on label.
5.02 If asituation arises that is
not covered in the
checklist, contact Tellabs Customer Service as
follows (telephone numbers are given below):
USA customers:
Contact Tellabs Customer Service
at your Tellabs Regional Office.
Canadian customers:
Contact Tellabs Customer
Service at our Canadian headquarters in
Mississauga, Ontario.
International customers:
Contact your Tellabs
distributor.
US atlantic region: (203)
798-0506
US capital region: [phone]
US central region: [phone]
US southeast region: [phone]
US
southwest region: [phone]
4. specifications US western region: (714)
850-1300
Canada: [phone]
5.03 If a 9908B is diagnosed as defective, follow
the replacement procedure in paragraph 5.04 when
acritical service outage exists (e.g., when asystem
or acritical circuit is down and no spares are avail-
able). If
the situation is not critical, follow the repair
and return procedure in paragraph 5.05.
replacement
5.04 To obtain a replacement 9908B sub-
assembly,
notify Tellabs via letter or telephone (see
addresses and numbers below),
or via TWX (910-
695-3530 in the USA, 610-492-4387 in Canada). Be
sure to provide all relevant information, including
the 8X9908B part number that indicates the issue
of
the subassembly in question. Upon notification,
we shall ship a replacement subassembly to you. If
the
subassembly in question is in warranty, the
replacement will be shipped at no charge. Pack the
defective 9908B in the replacement subassembly's
carton, sign the packing slip
included with the
replacement, and enclose it with the defective sub-
assembly (this is your return authorization). Affix the
preaddressed label provided with the replacement
subassembly to the carton being returned, and ship
the
subassembly prepaid to Tellabs.
repair and return
5.05 Return the defective 9908B subassembly,
shipment prepaid, to Tellabs (attn: repair and return).
in
the USA:
Tellabs, Inc.
4951 Indiana Avenue
Lisle, Illinois
60532
telephone [phone]
in Canada:
Tellabs
Communications Canada, Ltd.
1200 Aerowood Drive, Unit 39
Mississauga, Ontario, Canada L4W 2S7
telephone [phone]
Enclose an explanation of the subassembly's
malfunction. Follow
your company's standard pro-
cedure with regard to administrative paperwork.
Tellabs will repair
the subassembly and ship it back
to you. If the subassembly is in warranty, no invoice
will be issued.
page4

test procedure
testing guide checklist
normal result
practice section 8399088
if normal conditions
are not met,verify:
equalization,
HT
equalization,
8W
equalization,
SLOPE
Ensure
that host module's
level controls (or switches) are
set
for zero gain or loss. Also
ensure that EO/BYP switch
(S3) on
99088 is set to EO to
include equalizer in transmis-
sion path.
Set all BW switches
on 99088 to ON. Set all SLOPE
and HT switches on 99088 to
OFF. Arrange transmit portion
of transmission measuring set
(TMS) for 3250Hz tone output
at -20d8m and at appropriate
port impedance selected on
host module.
Connect this
signal
to appropriate input jack
(if available) or to appropriate
tip and ring pinouts on host
module. Arrange receive por-
tion
of TMS for properly ter-
minated measurement, and
connect it to appropriate out-
put
jack (if available) or to
appropriate tip and ring pin-
outs on host module. Set
99088's HT switches to ON
one at atime.
Maintain TMS
connections as
described above. Ensure that
all SLOPE switches on 99088
are set to OFF. Set all HT and
BW switches on 99088 to ON.
Arrange transmit portion of
TMS for 2500Hz tone output at
-20d8m. Set BW switches to
OFF one at atime.
Maintain TMS connections as
I
·described above.
Set all SLOPE,
BW, and HT switches on
99088 to OFF. Arrange trans-
mit
portion of TMS for 404Hz
tone output at -20d8m. Set
SLOPE switches to ON one at
atime.
Output level of host module
increases as equalization is
added D.
Output level of host module
decreases as equalization is
added D.
Output level of host module
increases as equalization is
added D.
page5
Switch S3 on 99088 set to EO
position D. TMS output level
and
frequency correct D. Ter-
minating impedances correct
D. Host module's level controls
and option switches correctly
set D. Replace subassembly
and retest D.
Switch S3 on
99088 set to EO
position D. TMS output level
and
frequency correct D. Ter-
minating impedances correct
D. Host module's level controls
and option switches correctly
set D. Replace subassembly
and retest D.
Switch 53 on 99088 set to EO
position D. TMS output level
and
frequency correct D. Ter-
minating
impedances correct
D. Host module's level controls
and option switches correctly
set D. Replace subassembly
and retest D.