User Manual

Table Of Contents
RF-Orchestra!™ Transmitter Installation and Operation System Description
July 2000 6880493G02-C 2-7
RF-O! Transmitter Functional Description
The RF-O! transmitter, using linear technology, efficiently uses spectrum in the new
narrowband Personal Communication System (PCS) 25- and 50-kHz channels. To achieve
high system capacity, the RF-O! transmitters benefit from frequency reuse techniques. Using
ReFLEX and InFLEXion protocols, the subscriber is always in contact with the RF-C! controller
allowing the RF-C! controller to target a specific transmitter as needed. The modular design
provides a variety of power levels while maintaining an average power level for the
InFLEXion protocol.
RF-O! Transmitter Features
The following paragraphs summarize the main features of the RF-O! transmitter.
Expansion
Modular PA building blocks create a platform that is easily expandable. For InFLEXion,
increasing the number of supported subchannels adds to message capacity while for ReFLEX,
expansion results in increased output power. Expansion from a single InFLEXion subchannel
transmitter to a 2 InFLEXion subchannel transmitter is accomplished by adding a PA,
combiner, cabling and/or other peripherals.
Power Control
The RF-O! transmitter power control feature maintains maximum power output under the
most adverse conditions. Power control comprises the following:
Power metering: The RF-O! transmitter FM power level is measured using both an
internal (PA output) and external wattmeter (TX cavity filter output) with support from
the DSP.
Power meter calibration: The RF-O! transmitter is calibrated to an independent power
meter traceable to the National Bureau of Standards.
Power leveling: The RF-O! transmitter power is constantly monitored so that the power
may be adjusted in fine increments to keep the measured power at a desired level.
Power set: The user may set the power levels individually for ReFLEX (FM modulation)
and InFLEXion (AM modulation). The parameter(s) are adjusted to maintain the
requested power levels based on the alignment parameters and the number of
subchannels.