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 …
dBm is the standard unit of measure for levels of power based on a one milliwatt (mW) reference signal. The dBm measurement is very similar to dB (decibel); however, dB is a relative measure of the power of an input signal while dBm is always an absolute value based on a single milliwatt. If there …
A heterodyne is a circuit that transfers a signal from one carrier wave to another with a different frequency. It mixes the input signal with a wave generated by an oscillator to create two new signals, called beats. While heterodyning is a simple process governed by the laws of trigonometry, most heterodynes are complex devices …
A multivibrator is an electronic circuit that rapidly switches because of positive feedback between multiple states. The switch’s output is harmonic. Three types of multivibrator circuits are used in industry today: astable, monostable, and bistaple. Types of Multivibrators The three multivibrator types are: Astable Multivibrator – The circuit is not considered stable in either of …
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 …
An isolation transformer is made of two copper coils that are wound around each other and are each supplied by their own power source. While the term “isolation transformer” technically refers to any transformer, it is specifically a transformer that isolates a circuit from an alternating current. An isolation transformer does this by separating two …
A spot beam is a beam of radio signals that is directed towards a specific area on the Earth’s surface. Spot beams are the opposite of broad beams, which are beams that are directed towards a large area of the Earth’s surface. While broad beams are used for general telecommunication and surveillance, spot beams are …
DIN stands for ‘Deutsches Institut für Normung’ which means ‘German Institute of Standardization’. DIN develops norms and standards as a service to industry, to the state and to society as a whole. It is a registered non profit organization which has been based in Berlin since 1917. It consists of nearly 1,700 members who include …
Television antennas are generally installed on top of buildings, which makes the entire structure susceptible to lightning strikes. In order to protect the building that the TV antenna is attached to, the antenna has to be grounded properly. Another danger of mounting a television antenna that is not grounded properly is the excessive static electricity …
Backward Error Correction, also known as an “Automatic Repeat Request” is an error correction technique in which a receiving device sends a request to the source device to re-send information. Backward Error Correction is used in situations where some of the transmitted data has been lost or corrupted during transit and the transmitting device must …