lowest-useful frequency
1Frequency — For other uses, see Frequency (disambiguation). Three cyclically flashing lights, from lowest frequency (top) to highest frequency (bottom). f is the frequency in hertz (Hz), meaning the number of cycles per second. T is the period in seconds (s) …
2Radio-frequency identification — (RFID) is a technology that uses radio waves to transfer data from an electronic tag, called RFID tag or label, attached to an object, through a reader for the purpose of identifying and tracking the object. Some RFID tags can be read from… …
3Variable-frequency oscillator — A variable frequency oscillator (VFO) in electronics is a oscillator with an oscillation frequency that can be electronically changed (hence, variable).cite book |title=The ARRL Handbook for Radio Amateurs, Sixty Eighth Edition |editor=Larry D.… …
4Maximum usable frequency — (MUF) describes, in radio transmission, using reflection from the regular ionized layers of the ionosphere, the upper frequency limit that can be used for transmission between two points at a specified time, independent of transmitter power. This …
5наименьшая применяемая частота — НПЧ Нижняя граница частотного диапазона, которая может быть использована для ионосферной связи в течение заданного периода времени. Ср. maximum usable . [Л.М. Невдяев. Телекоммуникационные технологии. Англо русский толковый словарь справочник.… …
6sound — sound1 soundable, adj. /sownd/, n. 1. the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other medium. 2. mechanical vibrations transmitted through an elastic medium, traveling in air at a… …
7Sound — /sownd/, n. The, a strait between SW Sweden and Zealand, connecting the Kattegat and the Baltic. 87 mi. (140 km) long; 3 30 mi. (5 48 km) wide. Swedish and Danish, Oresund. * * * I Mechanical disturbance that propagates as a longitudinal wave… …
8Waveguide — This page is about waveguides in the most general sense. For ordinary metal pipe waveguides, Waveguide (electromagnetism). For optical waveguides, see Waveguide (optics). A section of flexible waveguide with a pressurizable flange …
9T2FD Antenna — The T2FD (Tilted Terminated Folded Dipole) is a general purpose shortwave antenna developed in the late 1940s by the United States Navy [ An Experimental All Band Nondirectional Transmitting Antenna by Gil L. Countryman, W1RBK, (W3HH), QST, June… …
10Anechoic chamber — An anechoic chamber An anechoic chamber (an echoic meaning non echoing or echo free) is a room designed to stop reflections of either sound or electromagnetic waves. They are also insulated from exterior sources of noise. The combination of both… …
