Section 2
Installation
11
2.4
RIB-600Analog 600
BALANCED installation
The RIB-600Analog receiver can be connected to the 600
balanced MIC INPUT of a
public address amplifier when the receiver is not located close to the PA amplifier.
When an RIB-600Analog radio message is received, the RIB-600Analog receiver will send the audio to the 600
microphone input of the PA amplifier.
A typical balanced cable contains two identical wires, which are twisted together and then wrapped with a third conductor
(foil or braid) that acts as a shield. The wires are twisted together, to reduce interference from electromagnetic induction.
Twisting makes the loop area between the conductors as small as possible, and ensures that a magnetic field that passes
equally through adjacent loops will induce equal but opposite currents, which cancel out. The separate shield of a
balanced audio connection also yields a noise rejection advantage over an unbalanced two-conductor arrangement (such
as AUX IN) where the shield must also act as the signal return wire. Any noise currents induced into a balanced audio
shield will not therefore be directly modulated onto the signal, whereas in a two-conductor system they will be. This also
prevents ground loop problems, by separating the shield/chassis from signal ground.
Connections to the PA amplifier are through the Orange, Yellow, and Gray wires from the RIB-600Analog Interface Cable
per the table below. Connections between the shielded, twisted pair and the RIB-600Analog Interface Cable can be made
using 22AWG wire nuts.
NOTE:
To minimize noise it is often necessary to connect the ground shield at only one end of the cable.
PUBLIC ADDRESS AMPLIFIER
600
MIC-1
GND COM HOT
600
MIC-2
SPEAKER
COM 4
8
16
COM 25V 70V
UNSWITCHED
AUX INPUT
1 2
RIB-600Analog
PA Amplifier
ORANGE
connects to
HOT
or
“
+
” or
POS
YELLOW
connects to
COLD
or
“
-
“ or
NEG
or
COM
GRAY
connects to
GND
or
CHASSIS
or
SHIELDED,
TWISTED PAIR
RIB-600Analog
Receiver
