standard frequency and time signals
41Power dividers and directional couplers — A 10 dB 1.7–2.2 GHz directional coupler. From left to right: input, coupled, isolated (terminated with a load), and transmitted port …
42Electromagnetic radiation and health — Electromagnetic radiation can be classified into ionizing radiation and non ionizing radiation, based on whether it is capable of ionizing atoms and breaking chemical bonds. Ultraviolet and higher frequencies, such as X rays or gamma rays are… …
43Dual-tone multi-frequency signaling — One of the few production telephone DTMF keypads with all 16 keys, from an Autovon Telephone. The column of red keys produces the A, B, C, and D DTMF events. Dual tone multi frequency signaling (DTMF) is used for telecommunication signaling over… …
44Business and Industry Review — ▪ 1999 Introduction Overview Annual Average Rates of Growth of Manufacturing Output, 1980 97, Table Pattern of Output, 1994 97, Table Index Numbers of Production, Employment, and Productivity in Manufacturing Industries, Table (For Annual… …
45Variable-frequency drive — A variable frequency drive (VFD) is a system for controlling the rotational speed of an alternating current (AC) electric motor by controlling the frequency of the electrical power supplied to the motor.cite book | first=Sylvester J. |… …
46National Institute of Standards and Technology — NIST redirects here. For other uses, see NIST (disambiguation). National Institute of Standards and Technology Agency overview Headquarters Gaithersburg, Maryland …
47Near and far field — This article is about the electromagnetic concept. For the mathematical, see Near field (mathematics). Antenna field regions for antennas that are shorter than the wavelength of the radiation they emit, such as the whip antenna of a citizen s… …
48RAAF Signals Operator Technical — Signals Operators Technical work in the sensitive field of Signals Intelligence. They are required to collect and analyse foreign signals.Classification IssueTechnical Signals Intelligence is the most sensitive form of intelligence for the… …
49Sound recording and reproduction — Sound recorder redirects here. For the audio recording program computer software, see Sound Recorder (Windows). Sound recording and reproduction is an electrical or mechanical inscription and re creation of sound waves, such as spoken voice,… …
50X10 (industry standard) — X10 is an international and open industry standard for communication among electronic devices used for home automation, also known as domotics . It primarily uses power line wiring for signaling and control, where the signals involve brief radio… …
