RTU-292C Operations Manual
2-8
2.8.4
VOX SENSITIVITY
The RTU-292C VOX circuitry has four sensitivity levels: minimum, low, medium (factory
setting), and maximum. A higher setting will be more able to detect weak or noisy voice signals,
but will be more likely to false on ambient noise entering the telephone handset. A lower setting
will do the opposite. SW2-4 and SW2-5 control the unit’s VOX Sensitivity levels:
Table 2-6
VOX Sensitivity
SW2-4
SW2-5
VOX Sensitivity
Off
Off
Min
On
Off
Low
Off
On
Med *
On
On
Max
2.8.5
BALANCED/UNBALANCED RADIO INTERFACE
Internal jumper fields JP1 and JP3 set the unit for either a Balanced or Unbalanced audio interface
to the radio or other four-wire device connected to the J2 RADIO Connector. Set the jumper
plug across JP1 pins 2&3 for balanced input and across pins 1&2 for an unbalanced Receive
Audio input. Similarly, set the jumper plug across JP3 pins 2&3 for balanced TX Audio output
and across pins 1&2 for an unbalanced output. The factory setting for both input and output is
balanced.
2.8.6
RX LINE INPUT IMPEDANCE
The factory setting for the Receive Line input impedance is 600 Ohms, but if a high input
impedance for bridging is needed, the impedance may be set to approximately 47k Ohm. To set
to high impedance, move the jumper plug at JP2 from pins 1&2 (low, 600 ohms) to pins 2&3
(high, 47k ohms).
Summary of Contents for RTU-292C
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Page 35: ...RTU 292C Operations Manual 2 17 Figure 2 1 Outline Dimensions...
Page 37: ...RTU 292C Operations Manual 2 19 Figure 2 3 Location of Internal Option Settings...
Page 38: ...RTU 292C Operations Manual 2 20 Figure 2 4 Internal Option Settings Details...
Page 39: ...RTU 292C Operations Manual 2 21 Figure 2 5 Audio Interface Wiring Diagram...
Page 40: ...RTU 292C Operations Manual 2 22 Figure 2 6 Interface Details...
