Page 38 - The Illustrated Dictionary of Electronics

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amateur radio • AM/FM tuner 23

amateur radio 1. A general term, referring to the will cause no malfunction of, or damage to, a cir-
practice of operation, experimentation, and other cuit or device.
work in and related to the amateur service. 2. The ambiguity 1. Any unclear, illogical, or incorrect in-
hardware that comprises an amateur radio sta- dication or result. 2. The seeking of a false null by
tion. 3. A radio receiver, transmitter, or transceiver a servo. 3. In digital computer operations, an er-
that is specifically designed for operation in the ror resulting from improper design of logic.
amateur bands. ambiguous count In digital counters, a clearly in-
amateur radio operator Also called radio ham or correct count. See ACCIDENTAL TRIGGERING.
ham radio operator. An individual licensed to ambisonic reproduction A close approximation of
transmit radio signals in the amateur service. the actual directional characteristics of a sound in
amateur service A two-way radio service, existing a given environment. The reproduced sound al-
purely for hobby purposes (i.e., without pecu- most exactly duplicates the sound in the actual
niary interest). environment in which it was recorded.
amateur station A radio station licensed in the American Morse code (Samuel F. B. Morse, 1791–
AMATEUR SERVICE. 1872). Also called Railroad Morse. A telegraph
amauroscope An electronic aid to the blind, in code, at one time used on wire telegraph lines in
which photocells in a pair of goggles receive light the United States. It differs from the Continental
images. Electric pulses proportional to the light code, also called the International Morse Code,
are impressed upon the visual receptors of the which is used in radiotelegraphy. Compare CON-
brain through electrodes in contact with nerves TINENTAL CODE.
above each eye. American National Standards Institute Ac-
amber A yellow or brown fossil resin that is histor- ronym, ANSI. An industrial group in the United
ically important in electronics. It is the first mate- States that encourages companies to manufac-
rial reported to be capable of electrification by ture devices and equipment in accordance with
rubbing (Thales, 600 BC). Also, the words elec- certain standards. The objective is to minimize
tricity, electron, and electronics are derived from hardware incompatibility problems.
the Greek name for amber, elektron. American Radio Relay League A worldwide orga-
ambience The acoustic characteristic of a room, in nization of amateur radio operators, headquar-
terms of the total amount of sound reaching a lis- tered in Newington, Connecticut. The official
tener from all directions. publications are the monthly magazines, QST
ambient An adjective meaning “surrounding.” Often and QEX. They also publish numerous books and
used as a noun in place of the adjective-noun com- other educational materials.
bination (thus, “10 degrees above ambient,” in- American Standards Association Abbreviation,
stead of “10 degrees above ambient temperature”). ASA. At one time, the name of the national associ-
ambient humidity The amount of moisture in the ation in the U.S. devoted to the formation and dis-
air at the time of measurement or operations in semination of voluntary standards of dimensions,
which dampness must be accounted for. performance, terminology, etc. See ANSI.
ambient level The amplitude of all interference American wire gauge Abbreviation, AWG. Also
(acoustic noise, electrical noise, illumination, called Brown and Sharpe gauge or B & S gauge.
etc.) emitted from sources other than that of a The standard American method of designating
signal of interest. wire sizes. Wire is listed according to gauge num-
ambient light Also called ambient illumination. ber from 0000 (460 mils diameter) to 40 (3.145
Room light or outdoor light incident to a location mils diameter).
at the time of measurement or operations. americium Symbol, Am. A radioactive elemental
ambient-light filter In a television receiver, a filter metal first produced artificially in the 1940s.
mounted in front of a picture-tube screen to min- Atomic number, 95. Atomic weight, 243.
imize the amount of ambient light reaching the AM/FM receiver A radio set that can receive either
screen. amplitude-modulated or frequency-modulated
ambient noise 1. In electrical measurements and signals. Usually, a band switch incorporates the
operation, background electrical noise. 2. In demodulation-selection circuitry so that as the
acoustical measurements and operations, audi- frequency range is changed, the appropriate de-
ble background noise. tector is accessed.
ambient pressure Surrounding atmospheric pres- AM/FM transmitter A radio transmitter whose
sure. output signal can be frequency- or amplitude-
ambient temperature The temperature surround- modulated by a panel selector switch.
ing apparatus and equipment (e.g., room temper- AM/FM tuner A compact radio receiver unit that
ature). can handle either amplitude- or frequency-
ambient-temperature range 1. The range over modulated signals, and delivers low-amplitude
which ambient temperature varies at a given lo- output to a high-fidelity audio power amplifier.
cation. 2. The range of ambient temperature that Compare AM TUNER and FM TUNER.