Nautel NV7.5, Руководство по эксплуатации и обслуживанию

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NV10/NV7.5 Operations and Maintenance Manual Operating the transmitter
Page 2-82 Issue 3.4 2016-08-03
IBOC settings
This system setting (see Figure 2.55 on page 2-83 ) allows users to establish Forward Tap Delay,
FM+HD Low Inj Gain, FM+HD High Inj Gain and HD only system Gain levels. It also
allows for an IBOC power calibration. Changes apply to the active exciter (A or B) only. To
calibrate the other exciter, switch to the other exciter and repeat the change.
•
Forward Tap Delay
- This field displays the time delay (in unit taps) between the for-
ward path signal from the exciter and the reverse path signal into the exciter, fed back
from the output of the transmitter. This value is factory adjusted (to synchronize the
phase of the forward and reverse signals so that pre-correction can operate properly)
and should not require any adjustment in the field.
•
Auto-Find Gain
- Press the Start button to automatically find the optimized gain while
the transmitter is RF On and in the applicable preset mode/injection level.
•
FM+HD Low Inj Gain
- Applicable for FM+HD mode only (at -20dBc to -15.1dBc injec-
tion levels) and represents the starting/default gain applied to the forward path signal
within the exciter at initial turn on/ramp-up.
• FM+HD High Inj Gain
- Applicable for FM+HD mode only (at -15dBc to -10dBc injec-
tion level) and represents the starting/default gain applied to the forward path signal
within the exciter at initial turn on/ramp-up.
• HD Gain
- Applicable for HD mode only and represents the starting/default gain
applied to the forward path signal within the exciter at initial turn on/ramp-up.
• IBOC Power Calibration
- This calibration occurs at the factory and should not require
any adjustment in the field. This calibration is performed in FM mode.
• Calibration Value
- This field displays the calibration of the exciter’s measurement of
the transmitter power.