| 释义 |
superˈheterodyne, a. and n. Radio.
[f. supersonic a. (and n.) + heterodyne a.]
A. adj. Employing or involving a method of radio reception (also used in television) in which a signal from a tunable local oscillator is combined with the incoming carrier wave to produce an ultrasonic intermediate frequency whose value is fixed and predetermined, so that it is unnecessary to vary the tuning of the subsequent amplifier and detector and increased selectivity and amplification are possible.
1922Wireless World 1 Apr. 11/1 The Armstrong super⁓heterodyne principle, in which the incoming signals are heterodyned before the first detector valve. 1934Times Rev. Year 1933 1 Jan p. ix/4 Superheterodyne receivers were especially popular. 1966McGraw-Hill Encycl. Sci. & Technol. XI. 257/1 Frequency-modulation (FM) receivers are almost always superheterodyne. 1976Gramophone July 232/2 The superheterodyne circuit made modern radio possible. 1977W. Tute Cairo Sleeper vii. 128 ‘Hafiz the barman has a wireless set.’.. It was a superheterodyne job with valves.
B. n. A superheterodyne receiver.
[1921Q.S.T. May 16/1 If a good U.S. amateur with such a set and an Armstrong Super could be sent to England, reception of U.S. amateurs would straightway become commonplace.] 1922Ibid. July 7/1 Super-regeneration is..the method that makes two tubes do all the work that ten used to do in the super-heterodyne. 1933K. Henney Radio Engin. Handbk. xvii. 449 The h-f superheterodyne seldom has high sensitivity, unless the first or h-f tube is regenerative. 1940[see chassis 5]. 1965Wireless World July 336/2 The various oscillators in superheterodynes have all set their own problems. |