Telecast Fiber Systems
Powering Up
Note: Never try to move the power switch on any front panel without first pulling on the
switch lever to disengage its lock.
With power off at both units, check all electrical and optical connections as described
under “Installation” on page 1. Firmly seat and latch all connectors.
Power Switch Operation:
1. Pull the lever away from the panel.
2. Move it up for power on, or down for power off.
3. Switch on the power to both Adder 161 units.
The power switches at both units must be on for the system to function.
Verify that the green external power LEDs are illuminated, and that the red rx status
LED is not lit. If you do not get this result, refer to Troubleshooting on page 17.
Theory of Operation
The Adder 161 circuit block diagram is shown in Figure 11. The Adder 161 TX accepts
up to sixteen audio inputs and up to four digital inputs, and time division multiplexes
them onto a single optical fiber or coaxial cable. The system has two basic functions:
multiplexing signals onto an optical fiber or coaxial cable and demultiplexing these
signals.
11
+
−
Analog Inputs
ADDER 161 TX
ADDER 161 RX
Typ. 1 of 16
Typ. 1 of 4
Contact Closure Input
Digital Inputs
Analog Outputs
Typ. 1 of 4
Contact Closure Output
Digital Outputs
Receiver
Typ. 1 of 16
Typ . 1 of 2
Typ. 1 of 2
Optical
Multiplexer
+
−
Fiber
or
Coaxial
Cable
Transmitter
Demultiplexer
All signals on the fiber* are digital and, therefore, relatively insensitive to transmission
level variations. As a demultiplexer, the Adder 161 RX separates the multiplexed
signals it receives from the fiber and converts the audio information back into analog
signals. Coaxial cable may be optionally used instead of fiber optic cable.
There is a one-to-one correspondence between inputs and outputs at opposite ends of
the system.
*All references to transmissions on fiber also apply to the coaxial cable output.
Figure 11. Electronic Block Diagram
Summary of Contents for Adder 161
Page 2: ...Adder 161 ii...
Page 18: ...Adder 161 Figure 14 TX Audio Input Stage 14...
Page 25: ...Telecast Fiber Systems 21...
