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In
all
cases,
it
is
assumed
that
the
STL
is
a pair
of
land- lines,
a pair
of
microwave SIL ' s, or a PCM link.
There are four steps:
1)
Stereo Or Mono Installation: Adjust the
operating controls on
the Accessory
Chassis as follows:
Proof/Operate Switch:
OPERATE
Loudness Controller:
OFF
L and R Input Attenuators:
Clipping:
+ 2
Release Time:
10
Bass Coupling:
10
Gate Threshold:
HF Limiting:
10
2)
Stereo Or Mono Installation: Connect an audio oscillator to the LEFT INPUT
of
the Accessory Chassis. Set its frequency to lkHz, and its output level to
produce " OdB" + 3dB
as indicated
on the Accessory
Chassis TOTAL
MASTER
G/R meter.
[This
establishes a standard level at the output of the Accessory Chassis of
1.17Vrms (+ 3.6dBm) + 0.5dB
when its OUTPUT
ATTEN
is
fully
clockwise
and
when its balanced
output
is
loaded by 600
ohms. This
level
is
3.4dB
below
nominal
100% modulation in a 75us preemphasis system, although compressor
overshoots will produce peaks substantially above this level.]
If
the
STL
is
un-preemphasized,
adjust
the
Accessory
Chassis
OUTPUT
ATTEN
until
the STL
is
modulated 8dB
below its nominal
100%
modulation
level. In the case of a microwave STL, refer to the modulation meter on the
STL transmitter. In the case of a U.S.A.-standard land- line requiring a nominal
drive
level
of + 8dBm,
simply
turn the
Accessory
Chassis
OUTPUT
ATTEN
fully clockwise.
If
the
STL
is
preemphasized
at
50
or
75us,
adjust
the
Accessory
Chassis
OUTPUT
ATTEN
until
the STL
is
modulated
12dB
below
its
nominal
100%
modulation level.
Stereo Installation Only:
Repeat Step ( 2)
for
the
RIGHT
CHANNEL
of
the
Accessory Chassis, using the RIGHT CHANNEL STL.
Mono Installation Only: If you have two STL's
for redundancy,
repeat Step
(2)
using the RIGHT CHANNEL of the Accessory Chassis and the redundant
STL. If you have only one STL, proceed to the next step.
3.a)
Stereo
Installation
Only:
Reconnect
the
oscillator
to
the
LEFT
Accessory
Chassis input, and drive it with a lkHz tone at a level which produces a " 0"
reading on the TOTAL MASTER G/R meter. Connect the output of the LEFT
STL
receiver
to
the LEFT INPUT of the OPTIMOD-TV Main Chassis. Place
the VU meter FUNCTION switch in L COMPR OUT. Adjust the LEFT INPUT
ATTEN on the OPTIMOD-TV Main Chassis to make the VU meter read 100%.
(NOTE: Jumper Cards fi3TX and /14TX are shipped with 20dB pads ahead of
the input
amplifiers. If
the readings in
the L COMPR
OUT
position
of
the
Main Chassis
meter
are
too low with
the INPUT
ATTEN
fully
CW and
the
input
pads
are
strapped
for
20dB
attenuation,
restrap
them
for
OdB
attenuation. This
is
done
by moving the jumpers on Cards fi3TX
and
114TX
according to Fig. 3-3. The cards and subpanel are then replaced.
4-2
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