Radios

Software-Defined Radio (SDR) has really changed the way wireless communication systems are built and used by moving many functions from […]

Digital radio systems send information through the air using signals, but noise, interference, and other disruptions can mess with those

Wireless communication really depends on access to the radio spectrum, but honestly, a lot of it just sits there unused

Bandpass filtering sits at the heart of controlling which signals make it through an electronic system and which get blocked.

Digital Signal Processing (DSP) sits at the heart of how today’s radio receivers function. Instead of relying solely on analog

Packet radio lets digital data travel over radio waves in structured packets, not just in a continuous stream. It relies

If you’ve spent any time on the air, you know the High Frequency (HF) spectrum gives amateur radio operators all

QSL cards have been the go-to proof of a successful radio contact, whether it’s between amateur operators or shortwave listeners

HF digital modes have really changed amateur radio. They let people communicate reliably even when voice signals just don’t cut

Longwave radio communication uses very low frequencies to send signals over long distances, sometimes reaching hundreds or even thousands of

Medium wave radio signals act pretty differently depending on the time of day and what’s going on in the atmosphere.

Contesting and DXing add a real sense of adventure and competition to amateur radio. When you jump into contesting, you’re

Shortwave broadcasting uses high-frequency radio waves that travel thousands of miles by bouncing off the ionosphere. With just one transmitter,

MUF is the highest frequency that can support reliable ionospheric communication over a specific path, while LUF is the lowest

NVIS, or Near Vertical Incidence Skywave, is a high-frequency radio technique where you send signals almost straight up into the

Solar radio emissions are bursts of radio waves from the Sun that can mess with technology on and around Earth.

Shortwave radio signals can cross continents, but they sure don’t behave the same way every month. Sunlight, temperature, and atmospheric

Greyline propagation happens along that slim, shifting band where day meets night on Earth—the terminator. At dawn and dusk, the

Microwave radio communication needs precise, low-loss transmission of high-frequency signals. At the core of these systems, you’ll often find the

Radio astronomy digs into the universe by picking up radio waves that celestial objects emit. Unlike visible light, these long

High-frequency (HF) radio communication really leans on conditions in the upper atmosphere, and the Sun’s activity shapes those conditions a

Morse code, sent by continuous wave (CW) transmission, is still one of the most efficient and reliable ways to handle

CubeSats have really changed the way small-scale missions get to space. They offer a compact, affordable way to do things

FT8 lets amateur radio operators make reliable contacts even if signals are too weak to hear. It uses efficient encoding

A loop antenna uses a closed loop of conductive material to transmit or receive radio signals. Unlike a lot of

If you want to design a reliable communication system, you really need to understand how an antenna sends and receives

The ionosphere sits high up in the atmosphere, packed with charged particles that can bend, reflect, or sometimes just swallow

When you look at radio communication, the space around an antenna isn’t uniform at all. The electromagnetic field shifts its

Polarization of radio waves describes how the electric field moves as the wave travels through space. It decides how well

A ground plane antenna uses a vertical element and conductive radials, creating an efficient, omnidirectional signal. The radials act as

Digital modulation methods shape how today’s communication systems send information, whether over the air or through wires. By tweaking a

A Yagi-Uda antenna focuses radio signals into a narrow beam, so it’s great for applications where signal strength and direction

A dipole antenna uses a pair of conductive elements, usually metal rods or wires, to transmit and receive electromagnetic waves

Single Sideband (SSB) modulation refines amplitude modulation by using less bandwidth and power to send the same information. When you

An antenna really only works at its best when its electrical properties match the rest of the system. Impedance matching

A carrier wave really forms the backbone of radio communication, letting information travel efficiently over long distances. It’s basically a

Modulation techniques really drive modern communication systems, shaping the way information zips across radio waves, fiber optics, and even satellite

Radio waves are a type of electromagnetic energy that zip through space at the speed of light. They carry information

Electromagnetic wave propagation tells us how electric and magnetic fields move through space and different materials. Basically, it shows how

Frequency and wavelength shape how electromagnetic waves behave in the world. Frequency tells you how many wave cycles zip past

Automatic Gain Control (AGC) is crucial for keeping radio signals clear and steady. It adjusts the receiver’s gain on its

A superheterodyne receiver changes a radio signal from its original frequency to a fixed intermediate frequency before processing it. This

Thermal noise, which folks also call Johnson-Nyquist noise, shows up in every electrical conductor. It’s the result of random thermal

Noise is just part of the deal in every radio communication system. You’ll find it coming from all sorts of

Direct conversion receivers—often called zero-IF or homodyne receivers—go straight to the point in signal processing. They convert incoming radio frequency

Radio waves don’t always travel in straight lines. They bounce off surfaces, bend as they pass through different materials, or

Tropospheric ducting lets VHF and UHF radio signals travel much farther than you’d expect—sometimes well over a thousand kilometers. This

Every radio receiver relies on two main performance factors: sensitivity and selectivity. Sensitivity shows how well a receiver can pick

Atmospheric layers shape how radio signals travel, whether the distance is short or long. Each layer bends, reflects, or weakens

Wireless signals almost never just go in a straight line, uninterrupted. Buildings, terrain, and even layers of air can bounce,