Digital Aes/Ebu Left/Right Input/Output; Stereo Analog Baseband Composite Output; Subcarriers - Orban OPTIMOD-FM 8200 Operating Manual

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INTRODUCTION

Digital AES/EBU Left/Right Input/Output

The digital input and output follow the professional AES/EBU standard. The left/right
digital input is on one XLR-type female connector on the rear panel; the left/right digital
output is on one XLR-type male connector on the rear panel.
If digital AES/EBU left/right input or output is required and presently not installed, install
the Digital I/O Card according to the instructions provided with it.
The 8200 is designed to simultaneously accommodate digital and analog inputs and outputs.
You select whether the 8200 uses the digital or the analog input on the SYSTEM SETUP
I/O CALIB
active continuously. Level control of the AES/EBU input is via software control through
SYSTEM SETUP.
At the time of publication of this manual (January, 1995), there are two available versions
of the optional Digital I/O Card. The less expensive version (8200D/32) operates at a 32kHz
sample rate, the standard sample rate used for transmission of 15kHz bandwidth audio. Its
output is pre-emphasized to the 50µs or 75µs curve selected for the processing. It cannot
provide a "flat" output. The more advanced version (8200D/SRC) incorporates sample rate
conversion of 32, 44.1, or 48kHz.

Stereo Analog Baseband Composite Output

The stereo encoder has two unbalanced analog baseband outputs on two BNC connectors
on the rear panel. Each output can be strapped for 0Ω or 75Ω source impedance, and can
drive up to 8V peak-to-peak into 75Ω in parallel with up to 0.047
cable) before any noticeable performance degradation occurs.
Level control of each output is via a separate screwdriver control accessible from the front
panel.
A ground lift switch is available on the rear panel. This is useful to prevent ground loops
between the 8200 and the transmitter.

Subcarriers

The stereo encoder has an unbalanced 600Ω subcarrier (SCA) input with rear-panel BNC
connector to accept any subcarrier at or above 23kHz. The subcarrier will be mixed into each
composite output, and its level will be affected by the composite level control for that output.
The gain is scaled so that 1.5V peak at the subcarrier input produces 10% subcarrier
injection with reference to 100% deviation of the FM carrier.
If the stereo encoder is installed, a 19kHz TTL-level square wave is available on pin 18 of
the REMOTE INTERFACE, located on the rear panel of the unit. This provides a means for
synchronizing an external subcarrier generator, like an RDS (Radio Data Systems) subcar-
rier, to the 19kHz pilot tone.
screen or by REMOTE INTERFACE. Both analog and digital outputs are
Please note that the AES/EBU standard is not the same as the S/P-DIF
(Sony/Philips Digital Interface) standard used in consumer digital applica-
tions, such as the "digital outputs" of CD players. The AES/EBU interface
will not work with S/P-DIF signals.
OPTIMOD-FM 8200
µ
F (100ft/30m of RG-59/U