| 释义 |
ˈmotor-boating, vbl. n.
Also without hyphen and as two words.
[f. prec. + -ing1.]
1. Travel in a motor-boat.
1918Chambers's Jrnl. Aug. 541/1 The water is never dangerously rough, and provides the finest possible field for motor-boating. 1961Guardian 8 Feb. 10/2 The sports of motor-boating and water-skiing.
2. Electronics. Oscillation in an amplifier that is of such a low frequency that individual cycles may be heard, giving a characteristic sound, and caused by feedback from the output to the input of earlier stages, often through a common voltage supply.
1930J. H. Reyner Testing Radio Sets vi. 84 Back-coupling with a mains unit usually takes the form known as motor-boating. The oscillation set up is of a low frequency and gives a continuous ‘pop, pop, pop’. 1943F. E. Terman Radio Engineers' Handbk. v. 409 A power supply having low internal impedance at low frequencies is also helpful in eliminating motorboating. 1945Electronic Engin. XVII. 429 Regeneration may lead to low-frequency oscillation (about 5 to 10 c/s) known as ‘motor boating’. 1965G. J. King Radio & Audio Servicing Handbk. iii. 78 Decoupling prevents signals which could occur in an element common to two or more stages from getting back into the input circuits and causing oscillation or motorboating.
So ˈmotor-boat v. intr., (a) to travel in a motor-boat; (b) (of an amplifier) to exhibit motor-boating.
1922Contemp. Rev. Mar. 409 The scenery through which he tramped or motor-boated. 1932F. E. Terman Radio Engin. vii. 277 Amplifiers receiving their plate voltage from a common dry battery have a tendency to motor-boat when the batteries are near the end of their useful life, particularly when the amplification is high. 1970Nature 28 Nov. 797/2 Two men motor-boating on the loch collided with a large object. |