close frequency signals
71telephone — telephoner, n. /tel euh fohn /, n., v., telephoned, telephoning. n. 1. an apparatus, system, or process for transmission of sound or speech to a distant point, esp. by an electric device. v.t. 2. to speak to or summon (a person) by telephone. 3.… …
72Code division multiple access — This article is about a channel access method. For the mobile phone technology referred to as CDMA, see IS 95 and CDMA2000. Multiplex techniques Circuit mode (constant bandwidth) TDM · FDM  …
73Spectrum analyzer — A spectrum analyzer Spectrum analyzer display A spectrum analyzer measures the magnitude of an input signal versus frequency with …
74VHF omnidirectional range — This article is about the radio navigation aid. For other uses, see Vor. D VOR (Doppler VOR) ground station, co located with DME …
75Cab signalling — is a railroad safety system that communicates track status information to the train cab (driving position), where the engineer or driver can see the information. The simplest systems display the trackside signal aspect (typically, green, yellow… …
76electronics — /i lek tron iks, ee lek /, n. (used with a sing. v.) the science dealing with the development and application of devices and systems involving the flow of electrons in a vacuum, in gaseous media, and in semiconductors. [1905 10; see ELECTRONIC,… …
77Global Positioning System — GPS redirects here. For other uses, see GPS (disambiguation). Geodesy Fundamentals …
78Microphone — For the indie film, see Microphone (film). Microphones redirects here. For the indie band, see The Microphones. A …
79sound reception — Introduction response of an organism s aural mechanism, the ear, to a specific form of energy change, or sound waves. Sound waves can be transmitted through gases, liquids, or solids, but the hearing function of each species is particularly …
80General relativity — For a generally accessible and less technical introduction to the topic, see Introduction to general relativity. General relativity Introduction Mathematical formulation Resources …
