Axel Falcon VS, Руководство пользователя, Страница: 40 / 111

THE MPX GENERATOR
15.1.4 MPX
C
lipper
This value can be settable at between 95% and 105%, the MPX Clipper stage
operates within the pre-pilot region stage and is performed on the L + R and L-R
signals, before the pilot signal is entered. This design ensures that the clipping is
only performed on the composite signal, never on the Stereo Pilot signal.
The MPX Clipper stage can also be set to OFF via the same menu. When disabled,
the MPX Composite Clipper circuit is totally disconnected and not operational.
Whenever “aggressive” modulation is needed, i.e. a powerful increase in the sound density, at
the expense of sound 'definition', the cut point must be set at less than 100%, while any time
more “protected” modulation is required, the cut point must be set at over 100%
The Falcon XT clipping stage is based on the principle of maintaining a fixed clipping level and if it is increasing, it means
a positive gain must be applied to the modulated signal. If, instead, the clipping level is decreasing, a negative gain must
be applied to the modulated signal. The gain applied will be calculated according to the following formula:
Gain = 100% - "Clipping parameter" value point
Important : after setting the clipping parameter to 97%, the gain will be 100% - 97% = 3%, resulting in a density increase
of 3%. The final modulation level is always kept at 100%.
Conversely, if the clipping point is set at 104%, the gain applied will be 100% - 104% = - 4%, therefore a negative gain.
Without the clipping stage activated, the modulation peaks may surpass the 100% limit by as much as 3 or 5 kHz.
We therefore strongly recommend that you set the clipping level at 100%, which will avoid modulation distortions and
fully preserve the quality of the sound processed.
The clipping range (MPX Clipper) is designed so that, even when set at 95% (i.e. the maximum of the positive gain), the
Pilot Protection factor (19 kHz) is always kept above 60 dB.
15.1.5 MPX Output Mode
OPERATIVE MODES
STEREO
This is the device’s nominal operating or "stereo" mode, which includes all the
components within the MPX spectrum, as shown in the upper photo. It also includes the
RDS data carrier, if featured.
MONO
The MONO mode physically "switches off" the Stereo Pilot carrier at 19kHz. This way, the
receivers cannot decode the multiplex audio signal in "Stereo" mode. The RDS data
carrier can still be modulated.
TEST MODES
L+R
The MPX MAIN spectrum part and the Stereo Pilot are transmitted at 19kHz
L-R
The MPX SUB spectrum part and the Stereo Pilot are transmitted at 19kHz
PILOT
Solely the Stereo Pilot carrier is transmitted at 19kHz
NO PILOT
The entire MPX spectrum (Main and Sub) are transmitted at 19kHz but not the Stereo
Pilot carrier
| THE MPX GENERATOR - 40