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The basic signal consists of flashing red lights, a crossbuck and an alarm (either a bell, a speaker that mimics a bell sound or an electronic siren), attached to a mast. At most crossings, the signals will activate about 30 seconds before the train arrives but there are sensors measuring speed so that the crossing knows when to activate; so ...
EM34 tuning eye EM84 tuning indicator. A magic eye tube or tuning indicator, in technical literature called an electron-ray indicator tube, [1] is a vacuum tube which gives a visual indication of the amplitude of an electronic signal, such as an audio output, radio-frequency signal strength, or other functions. [1]
The end of train device (ETD), sometimes referred to as an EOT, flashing rear-end device (FRED) or sense and braking unit (SBU) is an electronic device mounted on the end of freight trains in replacement of a caboose.
The Yamaha PM1000 mixing console was a significant product in the professional audio industry because of its many advanced features and reasonable price. Introduced in 1974 it incorporated many innovative features such as a modular design using channel strips and output strips, a 4 bus design, and an output matrix mixer .
Zellweger is the brand name of an electric switching device also known as a Ripple Control Receiver used to control off-peak electrical loads such as water heaters by switching these loads OFF over peak energy use times of the day and switching them ON after peak energy use times of the day, hence the term 'off peak' control.
The television channel received by a TV occupies a wider bandwidth than an audio signal, from 600 kHz to 6 MHz. Terrestrial television receiver, broadcast television or just television (TV) - Televisions contains an integral receiver which receives free broadcast television from local television stations on TV channels in the VHF and UHF bands.
Imperfections in the glass create mirrors that reflect the light back along the fiber. [3] Impedance discontinuities cause attenuation, attenuation distortion, standing waves, ringing and other effects because a portion of a transmitted signal will be reflected back to the transmitting device rather than continuing to the receiver, much like an ...
Modern satellite television receivers use several intermediate frequencies. [6] The 500 television channels of a typical system are transmitted from the satellite to subscribers in the Ku microwave band, in two subbands of 10.7–11.7 and 11.7–12.75 GHz.