Motorola APX 3000 Detailed Service Manual page 464

Glossary-6
Term
phase-locked loop
PL
PLL
Power Control IC
private-line tone
squelch
Programmable
Read-Only Memory
PROM
PTT
Push-to-Talk
radio frequency
radio frequency
power amplifier
RAM
random access
memory
read-only memory
real-time clock
receiver
registers
repeater
A circuit in which an oscillator is kept in phase with a reference, usually
after passing through a frequency divider.
See private-line tone squelch.
See phase-locked loop.
The power control IC is intended for closed-loop bias control of power
amplifiers. The device facilitates accurate control of the current
delivered to the power amplifier (PA) via a control voltage.
A continuous sub-audible tone that is transmitted along with the carrier.
See also DPL.
A memory chip on which data can be written only once. Once data has
been written onto a PROM, it remains there forever.
See Programmable Read-Only Memory.
See Push-to-Talk.
The switch or button usually located on the left side of the radio which,
when pressed, causes the radio to transmit. When the PTT is released,
the unit returns to receive operation.
The portion of the electromagnetic spectrum between audio sound and
infrared light (approximately 10 kHz to 10 GHz).
Amplifier having one or more active devices to amplify radio signals.
See random access memory.
A type of computer memory that can be accessed randomly; that is, any
byte of memory can be accessed without touching the preceding bytes.
A type of computer memory on which data has been prerecorded. Once
data has been written onto a ROM chip, it cannot be removed and can
only be read.
A module that keeps track of elapsed time even when a computer is
turned off.
Electronic device that amplifies RF signals. A receiver separates the
audio signal from the RF carrier, amplifies it, and converts it back to the
original sound waves.
Short-term data-storage circuits within the microcontroller unit or
programmable logic IC.
Remote transmit/receive facility that re-transmits received signals in
order to improve communications range and coverage (conventional
operation).
Definition
Glossary