A Ham radio antenna tower is usually a metal tower that hams use to support their antennas. There's also an interesting story behind birth of the terms Ham or amateur radio. The actual signification of the term 'ham' was lost but there are several theories that explain its provenience. For example some say it was …
An opto isolator is an electronic device that prevents high voltages from components in one side of a circuit from damaging or interfering with components on the other side of the same circuit. Opto isolators regulate voltage levels by converting electricity into a beam of light. This prevents voltage spikes from impacting more than a single …
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 …
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, …
Electromagnetic Interference (EMI) most commonly occurs in the 104 to 1012 Hertz frequency range of the electromagnetic spectrum. A number of sources create this interference, including radio transmitters, electric motors, power lines, fluorescent lights, and computer circuits. If electrical equipment do not have suitable EMI shielding in place, device failure may result from the interference …
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 …
UHF is an acronym for a band of radio frequencies often used to broadcast television signals. Mobile phones and satellite radio also use UHF signals. The letters ‘UHF’ stand for: Ultra High Frequency. UHF Frequencies Any radio frequency between 300 MegaHertz (MHz) and 3,000 MHz (or 3 GigaHertz) is considered to be in the UHF …
An LNB (Low Noise Block aka LNC- Low Noise Converter) is used for communications (broadcast) satellite reception. The LNB is usually affixed either in or on the satellite dish. The LNB’s purpose is to utilize the super heterodyne effect and amplify and convert a wide block (band) of frequencies. This helps compensate the signal loss …
An infrared sensor is a device that emits and/or receives infrared waves in the form of heat. While most infrared sensors transmit and receive infrared waves, some can only receive them. These types of infrared sensors are known as Passive Infrared Sensors (PIR sensors) or motion detectors. What is an Infrared Detector? An infrared detector …
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 …