Orban OPTIMOD-FM 8700, Operating Manual

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2-6
INSTALLATION ORBAN MODEL 8700i
summed into the analog composite outputs in the analog domain and SCAs applied
to them do not appear on the digital composite output.
The Digital Composite cable plugs into the digital composite connector and provides
a 192 kHz AES3 composite baseband output (on an XLR connector), two SCA inputs
(BNC), and a wordclock/10 MHz reference input (BNC). Subcarriers applied to the
SCA inputs appear only at the digital composite output. To apply a subcarrier gener-
ator to both the digital and analog composite outputs, split the output of a subcar-
rier generator with a “tee” connector and apply it to both a digital composite SCA
input and a rear-panel SCA input.
When power is lost, bypass relays connect the analog L/R inputs to the analog L/R
outputs, the AES3 input to AES3 output #1, and the AES3 Sync input to AES output
#2. By setting J1 on the input/output board to the
C
OMP
B
ACKUP POSITION
,
Y
ou can
configure the analog SCA1 input as a composite backup input for use with a backup
processor or stereo encoder. When so configured, the analog SCA1 input will be
connected to analog composite output #1 when no power is applied. To locate J1, is
which close to the two BNC connectors, see page 6-51. See page 6-55 to identify the
settings of J1.
Audio Input and Output Connections
Cable
We recommend using two-conductor foil-shielded cable (such as Belden 8451 or
equivalent), because signal current flows through the two conductors only. The
shield does not carry signal and is used only for shielding.
Connectors

Input and output connectors are XLR-type connectors.
In the XLR-type connectors, pin 1 is CHASSIS GROUND, while pin 2 and
pin 3 are a balanced, floating pair. This wiring scheme is compatible with
any studio-wiring standard: If pin 2 or 3 is considered LOW, the other pin
is automatically HIGH.
Analog Audio Input

The 8700i will operate normally with nominal input levels between –14 dBu and
+8 dBu.
(0 dBu = 0.775Vrms. For this application, the dBm @600

scale on voltme-
ters can be read as if it were calibrated in dBu.)

The peak input level that causes overload depends on the setting of the Analog
Input
C
LIP
L
EVEL
control. It is adjustable from 0 dBu to +27.0 dBu.