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 …
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 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 …
Forward Error Correction (FEC) is a type of error correction that involves encoding a message in a redundant way, which allows the receiver to reconstruct lost bits without the need for retransmission. How Forward Error Correction Works FEC works by adding “check bits” to the outgoing data stream. Adding more check bits reduces the amount …
A Bessel filter is a linear filter that is used in electronics and signal processing and has a flat group delay (also referred to as a maximally linear phase response). These filters are commonly used in audio crossover systems and preserve the wave shape of any filtered signals across the group delay in the passband. …
ODU (Out-Door Unit) refers to the set of satellite equipment which is placed outside of the building. The ODU typically includes a satellite dish, a feedhorn, and a LNB (Low Noise Block). In bi-directional satellite systems, the ODU will also include a BUC (Block Up Convertor). The ODU is connected to the IDU (In-Door-Unit) by …
A frequency changer makes it possible to change electricity moving at one frequency to another frequency. However, in order to fully understand what a frequency changer does, it is helpful to understand the frequency of electricity. The Frequency of Electricity Electricity doesn't move at one specific speed. In fact, it can move at many speeds. …
A multimeter is used to take measurements of electrical properties for a circuit such as the voltage, current, or resistance. A modern multimeter combines the abilities of legacy voltmeters, ohmmeters, and ammeters. Some of the uses of a multimeter include electrical testing on electrical power sources, motors, and other electrical circuits or components. They are …
VSAT (Very Small Aperture Terminal) is basically a two-way satellite ground station with a less than 3 meters tall (most of them are about 0.75 m to 1.2 m tall) dish antenna stationed. The transmission rates of VSATs are usually from very low up to 4 Mbit/s. These VSATs’ primary job is to access the …
Hertz is the International System of Units (SI) base unit of measurement for frequency. Hz is the standard abbreviation for hertz. One hertz is defined as “one complete cycle per second,” and can be applied to any periodic event, but is usually applied to sound waves, electrical current, and radio waves. The hertz is the …