GMRS (General Mobile Radio Service) is a licensed radio service. GMRS consists of 16 UHF channels on FM, plus 7 channels that are shared with FRS. The maximum allowable power for a GMRS radio is 50 watts. The GMRS channels which are shared with FRS are limited to 5 watts of power. The use of …
DVB-RCS stands for Digital Video Broadcast – Return Channel Satellite. DVB-RCS is part of the DVB standards for satellite communication, DVB-S and DVB-S2. The purpose of DVB-RCS is to provide a return channel to enable Internet and other data services over satellite. ViaSat’s LinkStar system is one of the VSAT satellite broadband implementations which support …
Quadrature Amplitude Modulation (QAM) is a complicated name for a simple technique. In the simplest of terms, Quadrature amplitude modulation is the combination of amplitude modulation and phase shift keying. More technically, quadrature amplitude modulation is a system of modulation in which data is transferred by modulating the amplitude of two separate carrier waves, mostly …
A speaker is a device that converts electrical signals into actual sound. Speakers accomplish this by using a magnetic reader or antenna to receive an electrical signal from a radio station or magnetic storage device. The magnetic reader is then connected via a wire to an electromagnet that can be turned on and off in …
A galvanic isolator is any device that connects two circuits together without allowing electricity to flow directly from one circuit to the other. Instead of transferring electricity through direct contact, galvanic isolators use other means, such as electromagnetism, mechanical devices, optical systems, or acoustic systems to convert the electricity into another form of energy, transfer …
A solid state relay is a device that controls voltage to allow or prevent a voltage or current from passing through a circuit without using any moving parts. Solid state relays are commonly found in control systems that use large amounts of power and must be switched on and off on a regular basis. Solid …
An EMF meter detects and measures an electromagnetic field. There are many types of EMF meters and they have many uses, including ghost hunting. Most EMF meters are “AC EMF meters” and can only detect the rate of change in an oscillating magnetic field. However, commercial grade EMF meters that can detect specific electromagnetic frequency …
More properly known as the Bayonet Neill-Concelman connector, the BNC connector is one of several radio frequency connectors on the market today. The name of the connector is derived from a combination of two things: 1) the connecting technology employed; and 2) the names of the two inventors of the device. Paul Neill of Bell …
Some materials have the ability to produce electricity when subjected to mechanical stress. This is called the piezoelectric effect. This stress can be caused by hitting or twisting the material just enough to deform its crystal lattice without fracturing it. The effect also works in the opposite way, with the material deforming slightly when a …
Although radios have become less and less of a household commodity due to television, Internet, and media players, they are still used on a daily basis by millions of people worldwide. We tend to take these little devices, which we find in our cars, offices, or homes, for granted, but rarely think about how they actually …