GE ApexPro TT, Technical Manual

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2-18 ApexPro™ 2001989-351A
Equipment Overview
The RX network is directly connected by a network crossover cable to an ApexPro
Telemetry System. The RX network should not be tied to any other network.
rcrsysblk
Receiver System Block Diagram
Receiver subsystem (backplane)
The subsystem provides an interface between the quad receiver modules and the
telemetry software running on the ApexPro Telemetry System connected via 10BaseT
Ethernet. The subsystem accommodates up to four quad receiver modules. The
subsystem performs the initial amplification and filtering necessary on the RF input
signals from the transmitter.
Quad receiver modules
The quad receiver module receives the GMSK modulated RF signals from the
transmitter through the receiver subsystem (backplane). The RF signals are mixed to
an intermediate frequency, filtered, and mixed again to baseband and re-filtered. The
baseband signal is separated into its in-phase and quadrature components then
sampled. The DSP takes the samples, demodulates, corrects, and decodes packets of
TLINK data. The information is passed on to the receiver subsystem for further
processing and transport over Ethernet. Each module has four functionally identical
receivers.