18WuD2x

multiphase system • multiplex stereo 461
Transmitter
Ionized layer
multipath reception
Receiver
multiphase system See POLYPHASE SYSTEM.
multiple access system A timesharing data processing
system that can be used by a number of
people at remote locations, usually through peripherals
other than conventional terminals (e.g.,
cash registers linked to a computer system for inventory
control).
multiple-address code In computer operations, an
instruction code that requires the user to specify
the address of more than one operand per instruction.
multiple address instruction A computer program
instruction specifying the address of more
than one operand.
multiple break 1. Interruption of a circuit at several
points. 2. Contact bounce.
multiple-chip circuit See HYBRID INTEGRATED
CIRCUIT.
multiple connector In a flowchart, a symbol
showing the merging of several flowlines.
multiple ionization Successive ionization, as
when an ion repeatedly collides with electrons.
Also see DOUBLE IONIZATION.
multiple-length number In computer operations,
a number occupying more than one register.
multiple-loop feedback system A feedback system
using more than one feedback loop. An
example is a tunable audio amplifier (see
PARALLEL-TEE AMPLIFIER) in which a negativefeedback
path provides tuning, while a positivefeedback
path sharpens selectivity.
multiple modulation See COMPOUND MODULA-
TION.
multiple precision arithmetic An arithmetic process
using several words (bit groups) for an
operand to ensure accuracy.
multiple programming 1. Computer operation in
which several programs in memory share peripherals
and processor time. 2. Programming a
computer so that several logic or arithmetic
operations can be carried out at the same time.
multiple-purpose meter See MULTIMETER.
multiple-purpose tester A multimeter sometimes
combined with some other instrument, such as a
test oscillator.
multiple reel file In a data-processing system, a
magnetic tape data file of more than one reel.
multiple speakers A group of more than two loudspeakers,
usually operated from a single amplifier
system.
multiple-stacked broadside array A stacked array
in which a number of collinear elements are
stacked above and below each other. Also see
BROADSIDE ARRAY and COLLINEAR AN-
TENNA.
multiple station Descriptive of a communications
network in which more than one terminal is used.
multiple-unit steerable antenna A shortwave antenna
system intended to prevent or minimize the
effects of fading in received signals. It consists
principally of a number of rhombic antennas
feeding the receiver. The system utilizes the various
waves arriving at different angles. An electric
steering system causes the antennas to be selected
automatically in the best combination and
with their outputs in the proper phase. Also see
DIVERSITY RECEPTION.
multiple winding See DRUM WINDING.
multiplex Pertaining to a communications or
broadcasting system in which multiplexing is
used. See MULTIPLEXING, 1, 2, 3.
multiplex adapter A special circuit (or auxiliary
unit) used in frequency-modulated radio receivers
for stereophonic reception from a station
transmitting a multiplex broadcast. Also see
MULTIPLEXING, 1 and MULTIPLEX STEREO.
multiplex code The transmission of multiple signals
over a single medium, using a code (such as
Morse, Baudot, or ASCII). See MULTIPLEXING, 2,
3.
multiplex data terminal A computer terminal acting
as a modem by virtue of its accepting and
transferring signals between its input/output devices
and a data channel.
multiplexer A device that allows two or more signals
to be transmitted simultaneously on a single
carrier wave, communications channel, or data
channel. See MULTIPLEXING, 2, 3.
multiplexing 1. A process in which a comparatively
low-frequency carrier is modulated, then
mixed with a signal that has a higher frequency.
Also see SUBCARRIER and SUBSIDIARY COM-
MUNICATION AUTHORIZATION. 2. The simultaneous
transmission of numerous relatively
low-frequency signals on a single carrier having a
higher frequency. Also called frequency-division
multiplexing. 3. The transmission of numerous
signals on a single channel by breaking each signal
into timed fragments (intervals) and transmitting
the fragments in a rotating sequence. Also
called time-division multiplexing. 4. In certain digital
light-emitting-diode (LED) displays, the lighting
of various parts of the display in a rapidly
rotating sequence.
multiplex stereo The use of multiplexing to broadcast
both channels of a stereophonic program on
a single carrier wave. See MULTIPLEXING, 1, 2.