Nautel NX15, Operation And Maintenance Manual

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NX15/NX25 Operations and Maintenance Manual Operating the transmitter
Page 2-54 Issue 6.0 2019-01-31
•
AMSS -
Amplitude Modulation Signalling System. Allows low-bit rate data to be transmitted with the
Analog AM signal. Contact Nautel for assistance with using AMSS. Default is Disable.
NOTE
: The AMSS field is displayed only when the Overall Mode is Analog AM or DRM+AM.
• AES Input Level -
Defines the AES input level (in dBFS) that will result in 100% modulation depth. Set
between -30 dBFS and 0 dBFS, according to the input signal level.
•
Balanced Analog Input Level -
Defines the Bal Analog input level (in dBm) that will result in 100%
modulation depth. Set between -20 dBm and +12 dBm, according to the input signal level.
Digital Settings
( Figure 2.38 on page 2-57 through Figure 2.41 on page 2-58 )
For DRM and DRM+AM modes:
• Data Source -
Select the source for the OFDM (digital) signal (AES1 or AES2).
• AES input Level -
Defines the full-scale AES input level (in dBFS) for the I/Q stream. Set between -30
dBFS and 0 dBFS
•
DRM Bandwidth -
Selects the bandwidth of the DRM signal to be transmitted. This setting only sets the
parameters of the mask shown on the spectrum analyzer. Transmitted signal bandwidth is set at the I/Q
source (DRM modulator). Select 4.5 kHz, 5 kHz, 9 kHz, 10 kHz, 18 kHz or 20 kHz.
•
Frequency Offset -
Sets the frequency offset between the AM signal and the DRM carriers. Set between
-10 kHz and +10 kHz. In DRM mode, allows adjustment of the location of the OFDM carriers with
respect to the transmitter’s carrier frequency.
•
Power Differential -
In DRM+AM mode only, sets the difference between the AM carrier power and the
RMS power of the DRM carriers. The level is approximately based on the input signal to the exciter and
may require adjustment to obtain the exact level. Set between 0 dB and 40 dB.
•
Envelope Conditioning
-
In DRM mode only, applies a proprietary correction to the envelope to
improve spectral performance, but will negatively affect MER.