Nortel Networks RTU-292 Telephone User Manual


 
RTU-292 Operations Manual
2.8.3 VOX HANGTIME
The RTU-292 VOX circuitry holds the radio in the keyed state for a short time after the
telephone audio signal is no longer detected. This delay, called hangtime, ensures that the
VOX is not de-activated between syllables or during short pauses in speech. The standard
VOX hangtime duration is 2.0 seconds. Dipswitch SW2-6 allows the setting of 0.6 seconds
hangtime if required. The factory default setting, SW2-6 On, sets the VOX hangtime to the
longer 2.0 second setting, and SW2-6 Off sets it to 0.6 seconds.
Table 2-4 VOX Hangtime
SW2-6 Key Tone Detection
Off Short 0.6 seconds
On Long 2 seconds *
2.8.4 VOX SENSITIVITY
The RTU-292 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 2-5 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.
JPS Communications, Inc.
2-7