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Group 2. Stereo multiplex related parameters
MPX Positive
and
MPX Negative
- These bar graphs represent the positive and negative
deviation component of the
MPX signal
. In
wideband FM
, used in wireless broadcasting, the
instantaneous frequency varies above and below the frequency of the carrier with no modulation.
The carrier frequency shifts in one direction when the instantaneous input wave is with positive
polarity аnd vise-verse - when the instantaneous input wave is with negative polarity, the carrier
frequency shifts in the opposite direction. At every instant in time, the extent of carrier-frequency
shift (the deviation) is directly proportional to the extent to which the signal amplitude is positive
or negative.
Mod Input
FM Output
Pilot
– Represents the deviation caused by
Pilot tone injection
. Our practice shows that the pilot
deviation should be about 10% of the total deviation of the
RF carrier
.
RDS
– Represents the deviation caused by
RDS subcarrier
. Our practice shows that the
RDS
deviation
should be about 5% of the total deviation of the
RF carrier
.
Содержание DB7000
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