18WuD2x

462 multiplex telegraphy • multiprogramming
Subcarrier
oscillator
Mixer
RF
amplifier
f
Tuned to
mf
Out
Modulator
Reactancemodulated
oscillator
Power
amplifier
In
+12 V
AF amp.
AF amp.
Output
multiplier amplifier
Subsidiary
input
Main
input
multiplexing, 1.
multiplex telegraphy 1. A system of wire telegraphy
in which two or more messages are sent simultaneously
in one or both directions. 2. A
system of radiotelegraphy in which two or more
messages can be sent simultaneously on the
same carrier wave.
multiplex telephony 1. A system of wire telephony
in which two or more messages can be
sent simultaneously in one or both directions
over the same line. 2. A system of radiotelephony
in which two or more messages can be sent simultaneously
on the same carrier wave.
multiplication 1. The arithmetic process whereby
a certain factor is added to itself the number of
times indicated by another factor (the multiplier).
2. A method of increasing a quantity, magnitude,
or rate by some desired factor. See, for example,
FREQUENCY MULTIPLIER and VOLTAGE MUL-
TIPLIER.
multiplier 1. See FREQUENCY MULTIPLIER.
2. See VOLTAGE MULTIPLIER. 3. A circuit or
device for performing arithmetic multiplication.
4. See VOLTMETER MULTIPLIER.
multiplier amplifier A frequency-multiplying amplifier
(such as a doubler, tripler, or quadrupler),
whose output circuit is tuned to an integral multiple
of the input frequency. Compare STRAIGHT-
THROUGH AMPLIFIER.
multiplier phototube See PHOTOMULTIPLIER
TUBE.
multiplier prefix A prefix that, when affixed to the
name of a quantity (e.g., Hertz and byte) indicates
the amount, usually a power of 10 or a power of
2, by which that quantity is to be multiplied. Also
called prefix and prefix multiplier. See PREFIXES
table in Appendix B. Also see, for example,
GIGA-, KILO-, MEGA-, MICRO-, MILLI-, NANO-,
and PICO-.
multiplier probe 1. A resistor-type test probe for a
voltmeter, which increases the range of the meter
and, therefore, acts as a voltmeter multiplier. 2. A
voltage-multiplier type of test probe for a voltmeter,
which multiplies the test voltage before it is applied
to the instrument (e.g., voltage-doubler probe).
multiplier register In a computer, a register that
retains a number during a multiplication operation.
multiplier resistor A resistor connected in series
with a current meter (usually a milliammeter or
microammeter) to make it a voltmeter. Also called
VOLTMETER MULTIPLER.
multiplier tube See PHOTOMULTIPLIER TUBE.
multipoint circuit A transmission circuit or system,
in which information can be entered or retrieved
at two or more locations.
multipoint distribution service In radio broadcasting,
the transmission of programs via microwave
links from a central facility to various
local stations.
multipolar Pertaining to the presence of more than
two magnetic poles.
multipolar machine A motor or generator having
a number of poles in its armature and field.
multiposition relay A relay having more than two
positions of closure. See, for example, SELECTOR
RELAY.
multiposition switch A switch having more than
two contacting positions. See, for example, SE-
LECTOR SWITCH and STEPPING SWITCH.
multiprocessing 1. In a computer system, the
running of more than one program at once.
2. The use of more than one microprocessor
simultaneously in a single computer. Also called
parallel processing. 3. See TIME SHARING.
multiprogramming Also called multitasking. In a
computer system, a technique that allows two or
more programs to be executed at the same time.