MIRAGE MK III - Broadcast Audio Processor
AEV Broadcast Srl via della Tecnica 33, 40050 Argelato Bologna ITALY
www.aev.eu
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Gate Threshold
This control determines the threshold at which the processor becomes active.
This is adjustable from -10 to -10 dB. If the input signal level is less than the selected
threshold, both AGC DRIVE and RELEASE are disabled. This situation is indicated by the GATE
led.
Input Level
INPUT LEVEL is the input signal adjustment, made by two multiturn trimmers.
The input accepts signals from -20 to +10 dBm.
The level is correctly set when the AGC level, as displayed on the led bar (rear panel no. 1),
averages a value of 0.
Output Level
OUTPUT LEVEL is the adjustment of the output signal; the level is varied by the two multiturn
trimmers. The output is adjustable from 0 to +12 dBm.
The output should be adjusted for maximum allowable deviation at the transmitter
Pre-Emphasis and De-Emphasis
Before enabling pre-emphasis, the chapter entitled “Optimum control of the level of peak
modulation” should be read.
Attention Setup can be made by authorize personnel only.
MIRAGE features a dynamic pre-emphasis circuit. The configuration for pre-emphasis and
deemphasis is selectable with Dip-switch located in the rear panel.
De-emphasis need only be selected in those states that have a legal requirement for de-
emphasis at the transmitter.
ENCODER adjustment (*)
O
NLY FOR
MIRAGE FM MPX)
Pilot Level
This is the pilot signal level control which adjusts the level relative to the amplitude of
the MPX output signal. It can be adjusted via a trimmer.
Attention Setup can be made by author ize personnel only.
The signal excursion can vary between
4 and 12% of the optimum level (-20 dB with respect to 0 dBm of the MPX signal and is 10%
of the signal that produces ±75 KHz deviation).
Pilot Phase
This controls the phase of the 19 KHz pilot signal and allows the stereo separation to be
optimized by correcting the phase shift produced by the transmission chain.
To optimize the separation it is necessary to use a professional measurement decoder.
MPX Mode
This control enables the encoder modulator. Set the STEREO switch to change between MONO
and STEREO operation. In the mono position the 19 KHz subcarrier is automatically disabled.
Composite Out
This control adjusts the level of the MPX signal. The level may be varied between 0 dBm and
+12 dBm by adjusting the multiturn trimmer situated on the rear panel.
SCA Input Level
This control operates rather like that of RDS described above except that the range is from +6
dB to -14 dBm.
