Nautel VX150, Operation & Maintenance Manual

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VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL OPERATING THE TRANSMITTER
PAGE 2.2.44 VERSION 1.0 2022-12-08
• Pilot Level: enter value between 6 and 12% (typically 9%); this level is added to the composite
baseband.
• Pilot 1 PPS Sync: select Enabled or Disabled. If Enabled, enter:
– Pilot Sync Phase: (enter value between 0 and 360 degrees; typically 0 degrees).
• Audio Delay: Used to time align the receiver output of decoded analog and digital audio
signals. Select Enabled or Disabled. If Enabled, enter:
– Audio Delay Value: enter value between 0 and 20 seconds (default is 0).
• Mod (Modulation) Loss Timeout: select Enabled or Disabled. If Enabled, enter:
– Mod Loss Action: None (alarm only, no resulting action), Inhibit (inhibits the RF output
until the audio returns) or Change Preset (changes the active preset).
– Mod Loss Preset: displayed only if Action is set to Change Preset. Select the preset from
the drop down list that will activate upon the loss of a modulating signal, post the timeout
period. The original preset will not automatically return as the active preset if the audio/
modulation recovers. Manually re-select the active preset is required.
– Mod Loss Timeout Minutes: sets the delay, in minutes, between modulation loss detection
and the resulting action. Enter a value in the allowable range of 0 and 255 minutes.
– Mod Loss Timeout Seconds: sets the delay, in seconds, between modulation loss detection
and the resulting action. Enter a value in the allowable range of 0 and 59.9 seconds.
– Mod Loss Threshold: sets the threshold for modulation loss detection. Enter a value in the
allowable range of 0 and 100% (default is 0%). This feature uses the MPX baseband/peak
modulation level which includes RDS and SCA signals.
• Hard Limiter: If enabled, the modulation level will be limited (audio signal clipped or distorted)
if it exceeds the hard limit threshold. Select Enabled or Disabled. If Enabled, enter:
–
Hard Limit Value: enter value between 0 and 160% (default is 160%) .
NOTE
:
The RDS and Pilot signals are added to the RF output after the Hard Limiter is applied. This could
result in the output modulation exceeding the Hard Limiter threshold.
• AGC Limiter: If Enabled, when the modulation level exceeds the AGC Limit, the gain of the
audio input will instantly decrease in order to reduce the modulation level below the AGC limit
threshold. Recovery from this audio gain reduction is dependent on the Time Constant delay
(fast attack, slow recovery). The input signal is briefly distorted by the audio gain reduction
when the threshold is exceeded. Select Enabled or Disabled. If Enabled, enter: