Axel Falcon VS, Руководство пользователя, Страница: 41 / 111

THE MPX GENERATOR
15.2 MPX POWER LIMITER CONTROL (ITU-R BS.412)
The aim of standard
ITU-R BS.412 is to reduce the
density of the modulated signal while maintaining the
same peak deviation level, so as to keep co-channel
interference as low as possible.
Standard ITU-R BS.412 stipulates:
"It is assumed that the maximum peak deviation of ± 75 kHz is never exceeded. It is also assumed that the power of the
complete multiplex signal (including pilot tone and additional signals) over each 60-second interval is no greater than the
power of a multiplex signal containing a single sinusoidal signal which causes a peak deviation of ± 19 kHz. "
Essentially, the standard envisages the instalment of a sound treatment with a peak ratio of 12dB peak.
WARNING!
The default setting for MPX POWER CONTROL is ‘off’.
Many European countries are applying ITU-R 412. However, if the use of MPX POWER CONTROL is
not required by law in your country, make sure the control is switched off, as it could cause a loss of
output volume.
For example, with ITU BS-412 switched on and set at 0.0 dB, there is a volume loss of approximately
5-8 dB as against the same level with ITU BS-412 switched on.
To activate MPX POWER CONTROL, turn the MPX power control to ON. The power threshold can then be
increased from 0 to + 12 dB in 0.1 dB-steps. The output power calculation takes into account the pilot
injection values, the external RDS signal, and any SCA signals.
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