Nautel NV7.5, Operation And Maintenance Manual

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NV10/NV7.5 Operations and Maintenance Manual Operating the transmitter
Page 2-54 Issue 3.4 2016-08-03
Mode - additional calibration settings:
– IBOC Injection (Lower):
for
FM+HD
and
HD
modes, enter value, in dB,
between -20 and -10 dB for the IBOC injection level of the lower
sideband of digital carriers. This value determines the relationship
between the digital carriers power and the analog carrier power.
Example: -20 dB indicates that the total RMS power of the digital
carriers will be 1/100 of the total RMS power of the analog carrier. -10
dB indicates that the total RMS power of the digital carriers will be 1/10
of the total RMS power of the analog carrier.
– IBOC Injection (Upper):
for
FM+HD
and
HD
modes, enter value, in dB,
between -20 and -10 dB for the IBOC injection level of the lower
sideband of digital carriers. This value determines the relationship
between the digital carriers power and the analog carrier power.
Example: -20 dB indicates that the total RMS power of the digital
carriers will be 1/100 of the total RMS power of the analog carrier. -10
dB indicates that the total RMS power of the digital carriers will be 1/10
of the total RMS power of the analog carrier.
– HD PA Volts:
for
FM+HD, HD and DRM+
modes, enter value, in volts,
between 25.0 V and 53.0 V. This value sets the drain voltage applied
to the PAs in the RF power modules, from their associated power
supplies. This value affects
IBOC/DRM+
performance. Larger values
result in an improved spectrum, but decreased efficiency.
Conversely, smaller values result in improved efficiency, but degrade
Note:
The actual digital sideband power is 3dB less than that indicated in the upper or
lower IBOC Injection fields; i.e. if -20dBc is entered in the upper and lower IBOC
Injection fields, the upper and lower digital sideband power levels are actually -
23dBc; this way, when added, the resultant total digital power level is -20dBc.
For symmetrical sideband transmission: if -14dBc IBOC Injection level is desired
(total digital power of upper + lower sidebands is 4% of analog carrier power), set
the upper and lower IBOC Injection levels to -14dBc.
For asymmetrical sideband transmission, account for the fact that the actual
sideband power level is 3dB less than that shown. For example, if the upper digital
sideband IBOC Injection level is entered as -14dBc, the actual power level will be -
17dBc. This is equally true for the lower digital sideband.