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
~
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E9
iii;
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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
