Nortel Networks RTU-292 VOX Hangtime, VOX Sensitivity, BALANCED/UNBALANCED Radio Interface

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 *

2.8.4VOX 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

2.8.5BALANCED/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.

2-7 JPS Communications, Inc.