WisyCom MCR54 Series User Manual page 4

MCR54 User Manual
One of the milestones in the design of the MCR54 is unprecedented reliability: most of the circuitry
of the receiver is independent one from each other. Above a schematic with an overview of main
receiver functions.
RF layout:
For each antenna the RF signal is split in 4 to receiver 1,2,3 and 4 (antenna A and antenna B) with a
wide band splitter. Then 3 banks of filters are selected according to the frequency of the 4
receivers:
FILTER BANK 1:
FILTER BANK 2:
FILTER BANK 3:
NOTE: the tuning frequencies of all the 4 receivers has to be in the same bank of filter!
All the 4 receivers are true diversity receivers: each one is made of two receivers tuned on the
same frequency. Subsequently the selection of the band filter between 100 kHz or 200kHz allows
to work with Narrowband (High Density) or Wideband transmitters respectively.
Each receiver has its own demodulated signal and its own RSSI signal (Receiver Signal Strength
Indication); RF squelch used measurement of RSSI level for antenna diversity and for audio
enabling. In addition to the RSSI level, each receiver measures the Channel Quality. It is a more
powerful tool than RF squelch because it actually looks at the quality of the signal from the TX
relative to the noise floor on the channel which can vary over time. With the noise squelch set to
on you can set the RF squelch to a much lower level.
A DSP selects or combines signals from section A & B to have the best audio.
3
MCR54-B1 (UK)
470-800MHz Tuneable filter with 32MHz of bandwidth
961-1000 MHz
1045-1075 MHz
MCR54-B2 (USA/EU)
823-832 MHz
940-960 MHz
MCR54-B3 (JP)
806-810 MHz
1240-1260 MHz