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    • What is a Phototransistor?

      What is a Phototransistor?

      A phototransistor is a device that converts light energy into electric energy. Phototransistors are similar to photoresistors but produce both current and voltage, while photoresistors only produce current. This is because a phototransistor is made of a bipolar semiconductor and focuses the energy that is passed through it. Photons (light particles) activate phototransistors and are

    • LNB Tester

      LNB Tester

      Before you ask what an LNB tester is, you should know what an LNB is. An LNB is the receiving end of a satellite dish. LNB stands for low noise blocker; it is a device that essentially does what it says. It blocks low noise (frequencies) in order to receive higher frequencies in which satellite

    • QPSK (Quadrature Phase Shift Keying)

      QPSK (Quadrature Phase Shift Keying)

      QPSK (Quadrature Phase Shift Keying) is a phase modulation algorithm. Phase modulation is a frequency modulation version where the carrier wave’s phase is modulated to encode bits of digital information in each phase change. The “PSK” in QPSK refers to the use of Phased Shift Keying. Phased Shift Keying is a form of phase modulation

    • Shunt

      Shunt

      An electrical shunt is a component used to transfer currents away from parts of a circuit. Components used as shunts include the resistor, capacitor, diode, and gas discharge tube. The main uses for electrical shunts are to reduce current load in meters, filter out high frequencies, and protect circuits from surges. The term shunt is

    • Radio Repeater

      Radio Repeater

      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

    • Frequency Hopping Spread Spectrum

      Frequency Hopping Spread Spectrum

      The Frequency-Hopping Spread Spectrum (FHSS) is a means of transmitting radio signals by shifting a carrier across a number of channels with a pseudorandom sequence that the sending and receiving station knows beforehand. The method is used as a multiple access process in the FH-CDMA (Frequency Hopping Code Division Multiple Access) transmission scheme. What Are

    • dBm

      dBm

      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

    • ODU (Out-Door Unit)

      ODU (Out-Door Unit)

      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

    • How to Reset a Kenwood Security Code

      How to Reset a Kenwood Security Code

      Four digit security codes protect Kenwood car stereos from theft. If a thief steals a Kenwood car stereo, he/she will not be able to use the stereo until the secret four digit security code is entered. Unfortunately, many legitimate owners are also locked out of their Kenwood car stereos due to these security codes. This

    • Chebyshev Filter

      Chebyshev Filter

      A Chebyshev filter can either be analog or digital, and is an improvement on the Butterworth filter as it has a steeper roll-off and a greater passband and stopband ripple. These filters minimize overall error between actual and idealized filter characteristics for the designed range of the filter. The filter was named after Pafnuty Chebyshev,

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