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On Feb 22, 2000, Federal Signal Corporation announced the signing of a definitive agreement for the acquisition of P.C.S. Company. [4] On June 27, 2005, Federal Signal Corporation announced the signing of a joint venture agreement to establish a Chinese company, Federal Signal (Shanghai) Environmental & Sanitary Vehicle Company Limited, based ...
This circuit diagram shows the interconnections of parts for a very basic preselector which goes between and antenna and a radio. Source Drawn using free software by me using a well known circuit Date 2014-10-29 Author JNRSTANLEY. Permission (Reusing this file) See below.
The Federal Signal Company was an American manufacturer of railway signaling equipment in the early 20th century. It was located in Albany, New York . The company had been founded in 1905 as the Federal Railway Signal Company by former employees of the Standard Signal Company (Arlington, New Jersey). [ 1 ]
Omnidirectional antennas are widely used for radio broadcasting antennas, [3] and in mobile devices that use radio such as cell phones, FM radios, walkie-talkies, wireless computer networks, cordless phones, GPS, as well as for base stations that communicate with mobile radios, such as police and taxi dispatchers and aircraft communications.
An antenna array consisting of two such antennas, one above the other and driven in phase has a gain of up to 17 dBi. Being log-periodic, the antenna's main characteristics ( radiation pattern , gain, driving point impedance ) are almost constant over its entire frequency range, with the match to a 300 Ω feed line achieving a standing wave ...
At these lower frequencies, due to atmospheric noise (static) and man-made noise (interference), even a weak signal from an inefficient antenna is far stronger than the internal thermal or Johnson noise generated in the radio receiver's own circuitry, so the weak signal from a loop antenna can be amplified without degrading the signal-to-noise ...
This subsection could also be named "phased arrays", a type of composite directional antenna where the various component simple antennas are laid out a large fraction of a wavelength apart, with each antenna's feedline's phase individually shifted, so that the signal from a radio wave moving in some selected direction across the layout of the ...
Federal Signal Modulators (also known as Modulator Speaker Arrays) are electronic warning devices produced by Federal Signal Corporation that are used to alert the public about tornadoes, severe weather, earthquakes, fires, lahars, tsunamis, or any other disaster. They are identified mostly by their distinctive stacked "flying saucer" design.