Radio was not invented by any single person, but instead was a culmination of several scientists’ research, each of whom pioneered a different area of electromagnetic radiation and radio waves during the late 1800s and early 1900s. Among these men are well known researchers such as Heinrich Rudolf Hertz, James Clerk Maxwell, David E. Hughes, …
In order to deter theft, the majority of major automobile manufacturers implement a car radio security code. When the car stereo is removed from a vehicle, the device will not be usable until the unlock or security code is entered by the car owner or authorized repair facility. Unfortunately, some models of cars and trucks …
TV-GPS is a technology from Rosum Corporation of California. Basically, it is a GPS tracking technology that makes use of television broadcasting signals to intensify or strengthen GPS signals. It is slated for use in urban areas where most people own a television (so the TV broadcasting signals are extremely strong) and where the regular …
XM radio is one of the two primary satellite radio services in North America. The service is operated by Sirius XM Radio and publishes premium radio content in addition to more than 70 music channels, 39 news, ports, talk, and entertainment choices, 23 play-by-play sports channels, and 21 regional and weather channels. XM radio channels …
A transformer transfers electrical energy between two circuits. It usually consists of two wire coils wrapped around a core. These coils are called primary and secondary windings. Energy is transferred by mutual induction caused by a changing electromagnetic field. If the coils have different number of turns around the core, the voltage induced in the …
Standing Wave Ratio (SWR) meters are used to measure the standing wave ratio in a communications transmission line. The meter can display how much a transmission line and the load are mismatched (normally a radio antenna). It also determines how effective the impedance is of matching efforts. In CB and ham radio circles, the SWR …
Pulse position modulation is a signal modulation technique that allows computers to share data by measuring the time each data packet takes to reach the computer. It is often used in optical communication, such as fiber optics, in which there is little multi-pathway interference. Pulse position modulation exclusively transfers digital signals and cannot be used …
Low Earth Orbit (LEO) refers to a satellite which orbits the earth at altitudes between (very roughly) 200 miles and 930 miles. Low Earth Orbit satellites must travel very quickly to resist the pull of gravity — approximately 17,000 miles per hour. Because of this, Lowe Earth Orbit satellies can orbit the planet in as …
A Ham radio antenna tower is usually a metal tower that hams use to support their antennas. There's also an interesting story behind birth of the terms Ham or amateur radio. The actual signification of the term 'ham' was lost but there are several theories that explain its provenience. For example some say it was …
An opto isolator is an electronic device that prevents high voltages from components in one side of a circuit from damaging or interfering with components on the other side of the same circuit. Opto isolators regulate voltage levels by converting electricity into a beam of light. This prevents voltage spikes from impacting more than a single …