User Manual

RF-Orchestra!™ Transmitter Installation and Operation System Description
July 2000 6880493G02-C 2-29
RF-A! Receiver (Option X349, X351, X352, X353)
Transmitter sites can consist of an RF-O! transmitter and a co-located RF-A! receiver. A
maximum of four RF-A! receivers can be co-located in the 83-in. RF-O! paging station.
RF-A! receivers are required for receiving inbound messages. These messages include
registration, location, and acknowledgments from the pagers. Inbound messages are sent to
the RF-C! controller. A receiver site can be co-located with the transmitter sites, although some
stand-alone receiver sites may be required.
Each RF-A! receiver is a 19-in. rack-mount chassis that is two EIA rack units (3.5 inches) high.
Each RF-A! receiver receives signals on a single 12.5-kHz inbound channel. The receiver uses
diversity antennas to maximize signal gain in multipath environments. The RF-A! receiver
also uses advanced DSP demodulation techniques for inbound frequency shift keying (FSK)
messages at 800 and 1600 bits per second (bps). Whether co-located or stand-alone, all RF-A!
receivers support remote software downloads.
RF-A! Receiver Peripheral Package (Option X88, X89)
Optional receiver filtering is available to minimize interference by RF generating sources in
receiver range. An optional multicoupler provides for more than one RF-A! receiver to
interconnect to the receiver diversity antenna lines. The receiver multicoupler contains a low
noise amplifier and a splitter to distribute the receive signals to each RF-A! receiver. The
GPS receiver may be located on the reference module (Option X179) in the RF-B! transmitter
controller chassis or may be located external to the RF-B! transmitter controller module. The
transmitter network uses the GPS timing for synchronization. For sites with co-located
transmitters and receivers, the receivers monitor the GPS time and the 1-PPS timing from the
GPS receiver in the RF-B! transmitter controller. For sites with stand-alone RF-A! receivers, a
separate GPS receiver and antenna are required.
The RF-C! controller network that employs the GPS synchronization method requires a GPS
receiver at each transmitter site, at each stand-alone receiver site, and at the RF-C! controller.
Simulcast synchronization is accomplished by comparing the internal clocks of the RF-C!
controller and the RF-B! transmitter controller or the RF-A! receiver control module (at the
site) to the 1-PPS timing reference signal provided by the GPS receiver. The advantage of this
method of synchronization is that the distribution link need not be synchronous to maintain
synchronous operations.