IRLP – What is it? IRLP (Internet Radio Linking Project) was created in 1997 by Dave Cameron VE7LTD with the aim of providing links, via the internet, between amateur radio installations. The key philosophy behind the project was … Read More
A filter is an electric circuit (often called a network) that allows certain frequencies to pass but rejects (attenuates) other unwanted frequencies.In general, filters are one of four types – Lowpass, Highpass and Bandpass (Notch) … Read More
Vertical antennas, often simply known to amateurs as “verticals,” are antennas in which the driven element is vertical. Most common verticals are simply a piece of wire or aluminum tubing mounted vertically, but others, such as those designed for mobile … Read More
Mobile antennas are designed to be used for operation while in motion. Their uses include pedestrian mobile operation while walking, bicycle-mounted antennas for use while riding, and the most common form, automobile-mounted antennas for use … Read More
Resistance and Resistivity Resistance (R) is the measure of how much an object – a resistor – opposes the flow of electric current. The resistance of an object is measured in Ohms (<math>\Omega</math>) Resistivity (<math>\Rho</math>) is a measure of … Read More
What is a decibel dB? Some facts a decibel is the ratio of two power measurements decibels have no units decibels is a logarithmic relationship a decibel is 1/10 of a Bel decibels were created … Read More
What is SWR? When there is a mismatch between the output impedance of a transmitter and input impedance of an antenna, some of the signal – in the form of a wave – is reflected … Read More
What Is Capacitors? A capacitor, also known as a condenser, is a device that stores energy in an electrical field. Capacitors are open circuits to DC current, but their impedance drops as AC current passing through … Read More
Otherwise known as transmission lines, feedlines are used to transfer RF energy between a Transmitter, Receiver or transceiver and the antenna. Types Three types of feed lines are used by amateurs: Coax, Balanced Line, and Waveguide. … Read More
What is it? The sunspot cycle is generally known to be a cycle of approximately 11 years between successive peaks in sunspot activity. What is less known and understood is that with each successive 11-year … Read More