A software-defined radio (SDR) is one in which functions such as tuning, filtering and modulating/demodulating are performed by software rather than hardware. The ease with which this is now possible is due largely to advances in digital … Read More
The RTL2832 is an IC produced by Realtek Corporation to demodulate DVB-T (digital TV) signals and send them to a host computer over the USB bus. It has an additional mode designed to allow reception of consumer … Read More
What is it? A DX Cluster is, in essence, a “chatroom” or node into which amateur DX hunters can post information about DX either worked or heard. Physically, it is a central computer that collects, … Read More
Most people agree that the manual that comes with this radio is horrible. Let’s try to create a better one. Modes Hold U/V to switch between manual tuning and preset mode. In channel preset mode … Read More
The VHF Quagi from an article by Wayne Overbeck, K6YNB in QST April 1977; “Building a 440MHz Quagi” description is from Gary Bonnor – VK4ZGB There have been many half-hearted attempts to combine a Yagi … Read More
Software allows the production and detection of signals used for transferring SSTV pictures. Most SSTV software allows for both sending and receiving SSTV signals, with the ability to auto-detect which mode is being received. A … Read More
Simplified ionospheric models portray the ionosphere as a series of horizontal layers that vary with time, location and sunspot activity. The real ionosphere is much more complex than this, particularly in equatorial and polar regions. … Read More
A small transmitting loop, small tuned loop or magnetic antenna is defined as a loop antenna of less than one-tenth to one-quarter of a wavelength in circumference. These are normally constructed as a single turn of heavy-gauge wire (AWG #10 or larger), … Read More
Basics of Cavity Filter Cavity filters are the basic circuitry behind a Duplexer and are sharply tuned resonant circuit that allow only certain frequencies to pass. Generically, the filter of this kind is known as notch … Read More
What is Phonetic Alphabet? A number of phonetic alphabets exist. The NATO version is most common and can be considered to be the “international” phonetic alphabet. Letter Code Word Pronunciation A Alfa AL FAH B Bravo … Read More