The SMA (SubMiniature Type A) connector is a type of the radio frequency connector developed in the 1960s to make it easier to connect coaxial cables. Using a screw-type design instead of the common ‘push-pull’ system, the SMA connector allows for a quick connection; and can be used in both alternating and direct current applications. …
Yagi Antennas are one of the most well-known directional antennas in use throughout the world and are used for communications in the medium range of three to five miles between two points. They can also be used as a bridge antenna to connect clients to an access point. The original inventors of the antenna design …
Portable radios are limited in the power at which they can transmit, usually somewhere between .5 watts and 5 watts. A very rough rule of thumb is that one watt equals one mile of range over flat and open terrain. Buildings and mountains will, of course, greatly modify effective range. When two radios communicate directly …
Intersymbol interference is a signal distortion in telecommunication. One or more symbols can interfere with other symbols causing noise or a less reliable signal. The main causes of intersymbol interference are multipath propagation or non-linear frequency in channels. This has the effect of a blur or mixture of symbols, which can reduce signal clarity. If …
Generally, a transmission signal contains more than a single frequency. This is to say that there might be several different frequencies linked together or else superimposed on each other. This is just the way all telecommunication systems function. For example, with today's communication technology it is virtually impossible to send low frequencies without experiencing any …
A bug detector is a device that is able to locate and/or disable electronic spy equipment such as microphones, cameras, and GPS tracking devices. Law enforcement agencies, military counter-intelligence agencies, criminals, and everyday individuals who are suspicious of being overheard often use bug detectors. Bug detectors are usually small, portable, and have multiple display functions …
The military alphabet, or more properly the phonetic alphabet, exists in innumerable variants. If any military alphabet can be viewed as the most correct, it is the current NATO standard military alphabet. However, even with the NATO standard military alphabet, various member nations use numerous spelling variations. This version of the military alphabet is also …
A police scanner is basically a radio scanner that is also a receiver that receives wireless radio signals. A scanner identifies these wireless radio waves. A scanner can identify numerous radio signals and bands concurrently making it easy to keep track of many channels simultaneously. The phrase “police scanner” derives from the fact that 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 …
VSWR (Voltage Standing Wave Ratio) is a metric commonly used with antenna systems for ham or shortwave radio communication. VSWR is normally defined as a ratio with a 1:1 VSWR, indicating that there is an exact or perfect match between all antenna system elements. The VSWR can also be expressed by comparing Vmax with Vmin …