Search results
Results From The WOW.Com Content Network
The first use of a national emergency telephone number began in the United Kingdom in 1937 using the number 999, which continues to this day. [6] In the United States, the first 911 service was established by the Alabama Telephone Company and the first call was made in Haleyville, Alabama, in 1968 by Alabama Speaker of the House Rankin Fite and answered by U.S. Representative Tom Bevill.
A time-domain reflectometer; an instrument used to locate the position of faults on lines from the time taken for a reflected wave to return from the discontinuity.. A signal travelling along an electrical transmission line will be partly, or wholly, reflected back in the opposite direction when the travelling signal encounters a discontinuity in the characteristic impedance of the line, or if ...
If you haven’t heard much about Minnesota Gov. Tim Walz before Vice President Kamala Harris selected him as her running mate, you’re not alone. A new national NPR/PBS/Marist poll released ...
As AM signals have a modulation factor of only 30% by voltage at peaks [citation needed], no more than 9% of received signal power (= /) is actual audio information, and 91% is just rectified DC voltage. <correction> The 30% figure is the standard used for radio testing, and is based on the average modulation factor for speech. Properly ...
No soap radio. " No soap radio " is a form of practical joke and an example of surreal comedy. The joke is a prank whereby the punch line has no relation to the body of the joke, but participants in the prank pretend otherwise. The effect is to either trick someone into laughing along as if they "get it" or to ridicule them for not understanding.
The United States Army Signal Corps ( USASC) is a branch of the United States Army that creates and manages communications and information systems for the command and control of combined arms forces. It was established in 1860, the brainchild of Major Albert J. Myer, and had an important role in the American Civil War.
Fading. Frequency-selective time-varying fading causes a cloudy pattern to appear on a spectrogram. Time is shown on the horizontal axis, frequency on the vertical axis and signal strength as grey-scale intensity. In wireless communications, fading is the variation of signal attenuation over variables like time, geographical position, and radio ...
Small-signal model. Small-signal modeling is a common analysis technique in electronics engineering used to approximate the behavior of electronic circuits containing nonlinear devices with linear equations. It is applicable to electronic circuits in which the AC signals (i.e., the time-varying currents and voltages in the circuit) are small ...