User's Manual

Table Of Contents
MM102558V1 R1A
6.1.2.4 Receiver IF Module
The Receiver IF (RX IF) module models EA101401V1 (21.4 MHz for
VHF and UHF stations) and EA101794V1 (70.2 MHz for 800 MHz
stations), shown in
Figure 6-6, provides IF filtering, amplification, and
demodulation of the IF signal.
Output signals from the IF modules include a balanced 455 kHz IF
output for data applications and a demodulated audio output for analog
audio applications. The IF Module also provides AGC for the 455 kHz
IF signal and includes the receiver squelch circuitry.
Figure 6-6: Receiver IF
Module
6.1.2.5 System Module
The System Module 19D902590G6, shown in
Figure 6-7, uses
programmable microcomputer technology to control the base station's
transmitter, receiver, and audio processor. This module contains a Digital
Signal Processor (DSP) used for audio processing, tone generation and
detection.
The System module can be programmed for up to twelve (12) channel
operation during local control or programmed for remote control
applications. DC remote control features can control up to two (2)
transmit and receive frequencies, while Tone remote control can control
up to four transmit and receive frequencies.
Options provided by the Control Section include a transmitter Drop-Out
Delay (DOD) timer, Carrier Control Timer (CCT), Channel Guard (CG),
and Squelch Operated Relay output (SOR). The CCT is programmable
from zero to 10 minutes. The DOD is programmable from zero to 10
seconds. Additional station options include:
Battery alarm tone
Type 90 or DTMF tone decoding
2/4 wire audio
Morse code station identification
Auxiliary control
Figure 6-7: System
Module
46