Solder is a metal with a low melting point that is used to create the conductive joints between components and tracks in electrical circuits. There are many types of solder used for different metals, but the most common solder used for electronics is an alloy of tin and lead. Solder Flux Flux is essential for making good solder joints. It removes the thin film of surface oxidation that prevents two metals sticking together. It also prevents more oxidation occurring during soldering. Heat causes the flux to change it's chemical structure Read More

Traditional radio equipment works because all parties involved in the communication agree on what frequencies they will utilize. Traditional radio scanners work by scanning for and then listening to those frequencies. Trunking radios, on the other hand, constantly renegotiate the frequencies utilized for the conversation. This allows for more efficient utilization of limited frequencies because each conversation does not require a dedicated channel. However, it also makes it very difficult to scan trunked conversations because you do not usually know what frequency the next portion of the conversation will appear Read More

MURS, or the Multi-Use Radio Service, is a public radio service created by the FCC in the Fall of 2000 that can be accessed by any individual for personal or business-related purpose. MURS was created for the general public to use without acquiring a license to broadcast, but requires that users remain within the frequencies allotted to MURS. Officially, MURS is defined by the FCC as a “a private, two-way, short-distance voice or data communications service for personal or business activities of the general public.”   Rules of MURS Although Read More

Weather satellites are now operated by the United States, Japan, Europe, Russia, India, and China. These weather satellites provide invaluable information to meterologists and climatologists. In addition, individuals all over the globe enjoy these fascinating pictures of the Earth from outer space. Free Weather Satellite Images on the Web The NOAA's Geostationary Satellite Server provides visibile light, infrared, and water vapor images of the Continental United States, Puerto Rico, and Alaska and the Pacific, Gulf Atlantic, Atlantic, Gulf of Mexico, and East Coast. These images are created by NOAA's GEOS Read More

An oscillator is a circuit that creates a waveform output from a direct current input. The two main types of oscillator are harmonic and relaxation. The harmonic oscillators have smooth curved waveforms, while relaxation oscillators have waveforms with sharp changes. How Oscillators Work A basic oscillator is a capacitor and inductor connected together. As the capacitor discharges, the current creates a magnetic field in the inductor. When the capacitor is fully discharged, the field collapses and induces an opposite current that charges the capacitor again. This cycle continues until all Read More

A retrograde orbit is an orbit where the satellite travels in an East to West direction instead of the common West to East orbit. The normal West to East orbits are known as prograde orbits. Retrograde orbits are uncommon due to the much higher velocities necessary for successful launch and the associated higher costs. During a prograde launch, rotational velocity of the Earth is added to the velocity of the launch rocket. In a retrograde launch, the rotational velocity of the Earth is subtracted from the velocity of the launch Read More

Radio was not invented by any single person, but instead was a culmination of several scientists’ research, each of whom pioneered a different area of electromagnetic radiation and radio waves during the late 1800s and early 1900s. Among these men are well known researchers such as Heinrich Rudolf Hertz, James Clerk Maxwell, David E. Hughes, Thomas Edison, and Nikola Tesla. The Role of James Clerk Maxwell In order to fully understand the invention of radio, we must go back to an earlier point in time when electromagnetism was first discovered. Read More

An integrated circuit (IC), also called a microchip, is an electronic circuit etched onto a silicon chip. Their main advantages are low cost, low power, high performance, and very small size. History The integrated circuit was invented in 1958 by Jack Kirby (1923-2005), an American engineer. In 2000, he won the Nobel prize in physics for his integrated circuit. This basic design has evolved over the last half century to reach the level of the modern computer chip, which has millions of transistors on a thumbnail size piece of silicon. Read More

GPS stands for Global Positioning System. It is used by individuals, commercial entities and the military for navigational purposes. GPS uses 24 satellites that orbit the earth and send radio signals. The GPS satellites work with a GPS receiver which today can be found in individual handheld units, car navigational systems, boat navigational systems, highly precise commercial products and a wide range of military equipment. Operation of GPS GPS operates using triangulation. Triangulation is a method in which three separate points are measured to calculate location. For instance, in a Read More

A Butterworth filter is a signal processing filter that has an extremely flat frequency response in the passband. It is referred to as a maximally flat magnitude filter and is commonly used in both analog and digital audio crossover filters in home, commercial, and car stereo systems. Who Invented the Butterworth Filter? British engineer, Stephen Butterworth developed a reputation for being able to solve extremely difficult if not impossible mathematical problems. When Butterworth was conducting his research, most filter designs were a result of trial and error due to the Read More