Motorola ASTRO SPECTRA Service Manual

6881076C20-E February 3, 2003
Glossary-5
MOSI See Master Out Slave In.
multiplexer An electronic device that combines several signals for transmission on
some shared medium (e.g., a telephone wire).
MUX See multiplexer.
NiCd Nickel-cadmium.
NiMH Nickel-metal-hydride.
OMPAC See over-molded pad-array carrier.
open architecture A controller configuration that utilizes a microprocessor with extended
ROM, RAM, and EEPROM.
oscillator An electronic device that produces alternating electric current and
commonly employs tuned circuits and amplifying components.
OSW See outbound signaling word.
OTAR See over-the-air rekeying.
outbound signaling
word
Data transmitted on the control channel from the central controller to the
subscriber unit.
over-molded pad-
array carrier
A Motorola custom IC package, distinguished by the presence of solder
balls on the bottom pads.
over-the-air rekeying Allows the dispatcher to remotely reprogram the encryption keys in the
radio.
PA Power amplifier.
paging One-way communication that alerts the receiver to retrieve a message.
Patriot IC A dual-core processor that contains an MCU and a DSP in one IC
package.
PC Board Printed Circuit Board. Also referred to as a PCB.
phase-locked loop A circuit in which an oscillator is kept in phase with a reference, usually
after passing through a frequency divider.
PL See private-line tone squelch.
PLL See phase-locked loop.
private-line tone
squelch
A continuous sub-audible tone that is transmitted along with the carrier.
See also DPL.
Programmable
Read-Only Memory
A memory chip on which data can be written only once. Once data has
been written onto a PROM, it remains there forever.
PROM See Programmable Read-Only Memory.
Term Definition

Motorola ASTRO SPECTRA Specifications

General

Frequency Range	136-174 MHz, 403-470 MHz
Number of Channels	Up to 255
Channel Spacing	12.5 kHz, 20 kHz, 25 kHz
Modulation	FM
Operating Temperature	-22°F to +140°F (-30°C to +60°C)