DESCRIPTION
The synthesized ORION mobile radio combinations are
completely solid-state, utilizing microcomputer technology
and integrated circuits to provide high-quality,
high-reliability radios. Standard combinations may be
equipped with:
•
Microcomputer Controlled Frequency Synthesizer
•
Up to 16 Channels
•
0.0002% Frequency Stability
•
Other Structured Options
The basic radio consists of three printed wiring boards
mounted in a cast aluminum frame. The three boards are:
1. The Control Logic/IF board,
2. The Frequency Synthesizer/Receiver/Exciter board,
3. The Power Amplifier board.
The radio is of double-layer construction with tuning ad-
justments easily accessible from the top of the radio.
The Control Logic/IF Board located on the top of the ra-
dio, while the Power Amplifier and the Synthesizer/Re-
ceiver/Exciter boards are located on the bottom.
SYNTHESIZER/INTERCONNECT
The synthesizer consists of a microcomputer, Electrically
Erasable Programmable Read Only Memory (EEPROM), a
frequency synthesizer IC, transmit and receive Voltage Con-
trolled Oscillator’s (VCO) and associated circuitry. The fre-
quency synthesizer under control of the microcomputer
generates all transmit and receive Radio Frequencies (RF).
The EEPROM stores binary data for all radio frequen-
cies, Channel Guard tones/digital codes and the timing func-
tion of the Carrier Control Timer (CCT). The
microcomputer accesses the EEPROM and provides the cor-
rect WALSH bits to the Channel Guard circuitry to generate
the correct Channel Guard tone or digital code on a per-
channel basis.
PROGRAMMING
The EEPROM allows the radio to be programmed or repro-
grammed as needed to adapt to changing system requirements.
Radio Frequencies, Channel Guard tone and digital codes and
the CCT function can be reprogrammed.
The EEPROM can be reprogrammed through the radio
front connector using a personal computer. This programmer
allows all information to be loaded simultaneously.
Programming instructions are provided in the respective
Programmer Maintenance Manuals.
TRANSMITTER
The transmitter consists of the exciter, frequency synthe-
sizer, transmitter VCO and a Power Amplifier (PA) assembly.
The PA assembly consists of a PA board mounted on a heat
sink assembly. The PA board also contains an antenna switch-
ing diode and a low-pass filter.
Audio and Channel Guard circuitry for the transmitter is lo-
cated on the Logic Board.
RECEIVER
The receiver consists of the frequency synthesizer, RX
VCO, injection amplifiers, front end, IF and limiter detector.
Audio, squelch and Channel Guard circuitry for the receiver is
located on the Logic Board.
LOGIC FUNCTION
A microprocessor on the Control Logic/IF board controls
the frequency synthesizer, the TX ON/OFF, the decoding of
CTCSS tones, the generation of CTCSS tones,... etc. The audio
processor circuitry of the transmitter and the receiver are lo-
cated on the Control Logic/IF Board. Squelch circuitry and a
connection to the digital AEGIS circuit is also located on the
Control Logic/IF Board.
OPERATION
Complete operating instructions for the ORION Two-Way
Radio are provided in Operator’s Manual LBI-38888 for the
control unit used.
MAINTENANCE
The Service Section in maintenance manual LBI-38993
contains the maintenance information to service this radio. The
Service Section includes:
•
Dissassembly Procedures
•
Replacement of IC’s, chip capacitors and resistors
•
Alignment procedures for the transmitter and receiver
•
Troubleshooting Procedures and wave forms
Figure 1 - ORION Mobile Radio
SPECIFICATIONS* - Cont.
Receiver - Cont.
Selectivity:
EIA Two-Signal Method
(25 kHz Channels)
Spurious Response:
-95 dB (STD)
-100 dB (STD)
Intermodulation 30 kHz:
-85 dB (STD)
Maximum Frequency Separation:
136-153 MHz .... 17 MHz
150-174 MHz .... 24 MHz
Frequency Response:
1, -3 dB of 6 dB/octave de-emphasis from 300 to
3000 MHz (1000 Hz reference)
RF Input Impedance:
50 Ohms
Hum/Noise ratio:
Unsquelched
-50 dB
Squelched
-70 dB
Channel Spacing:
30 kHz
*
These specifications are intended primarily for use of the service technician. Refer to the appropriate Specifications Sheet
for the complete specifications.
LBI-38903
2
