Operating Informations - WisyCom MRK960 User Manual

MRK960 dual true diversity receiver

OPERATING INFORMATIONS

RF Level led bars
Two RF level led bars for each receiver indicate measured RF level at the antenna input of the receiver in the
selected channel. For a typical diversity reception it is a good starting point to consider that the two signals
should have the same average level over time, but this could be different while moving the transmitter on the
stage. The important issue is that moving the transmitter on the stage, the diversity has to work switching
from one receiver to the other receiver as indicated by the two blue leds on the top of the bars. When the
RF levels of the two inputs have similar level, the diversity control enable the two receiver at the same time,
further increasing the S/N ratio at the audio output.
Modulation led bar
The third led bar of each receiver indicates current channel modulation as percentage of nominal deviation
(not the audio output level). The difference between modulation and audio level is because normally there is
a preemphasis on audio transmission and some manufacturer uses different compression values and different
audio frequency equalization. Therefore to have the maximun efficiency of the radio channel it is important
to use the highest modulation bandwidth possible, in respect to the dynamic range of the audio signal and the
manufacturer specifications. If the receiver MRK950 has the DSP board option, the scale of the modulation
will be changed according to the nominal modulation of the type of microphone and manufacturer selected
in the NOISE REDUCTION SYSTEM. The modulation led bar is blank when the squelch and/or the tone squelch
opens the audio output circuit (or if there is no modulation on the transmitter, of course). Adjust the gain of
the audio chain in the transmitter to have in the maximum modulation peaks the 100% of modulation band-
width, leaving the next 6dB of modulation margin before clipping (red PEAK led) for extra sound pressure
margin. If the audio level is not exactly known, be conservative and adjust the microphone gain in a lower
position to avoid clippings during the working session.
Battery indication
On the main display of each receiver is always well visible the battery status of the transmitter (area 12 of the
main view). The resolution of the indication depends on the transmitter. Wisycom transmitters send 8 levels
of battery charge status, other competitors 6 or 4 or 3 level (full, half, empty).
When the transmitter is a Wisycom, the display of the batteries indicate the correct icon and the percentage
of the charge but, when the charge reach the 25% the battery area on the display became flashing, when the
charge reach the 12,5%, the illumination of the display is flashing to give an high visibility alarm to the user.
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