DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
The radio category groups together posts that are about complete radios and operating rather than individual circuits—transceivers, receivers, handhelds, SDR rigs, and real‑world operating notes. You’ll find write‑ups on rigs like Curumim, sBitx, ZBitx, Baofeng UV‑5R Mini, uBITX experiences, and other commercial or homebrew radios, often with a strong “how it actually behaves on the bands” focus.
Ashhar Farhan has officially unveiled the zBitx v2, a significant leap forward for the compact SDR transceiver. With upgraded hardware including a passive FET mixer and a game-changing Wi-Fi-based front-panel connection, the v2 fixes legacy bugs while paving the way for custom user interfaces.
Analog FM is hitting its limits. Enter DRM+, the open-standard digital revolution that brings CD-quality audio, multimedia data, and emergency alerts to the 88–108 MHz band. Explore the technology and global adoption of 2026.
This 6 meter antenna gives you strong, stable performance with a simple build. It covers a wide range, holds a good match, and behaves like a compact directional array.
On the day Israel and the United States launched their first strikes against Iran, a mysterious shortwave radio station flickered to life on 7910 kHz. It hasn’t gone silent since. Broadcasting streams of numbers in Farsi — a Cold War spy radio technique that was thought to be fading from use — the signal has now been logged from Europe to North America. Radio amateurs have given it a name: V32
Slow Scan Television (SSTV) is a fascinating mode that allows you to send and receive still images over HF radio using your SSB transceiver. The uBITX and similar homebrew/commercial SSB radios are excellent platforms for SSTV operation. This comprehensive guide will walk you through the complete setup process.
Learn how to build a high-performance HF Linear Push-Pull Power Amplifier using affordable IRF510 MOSFETs. This guide includes a full schematic, bias adjustment tips, and transformer winding details for 10-40W output across the HF bands.
Upgrade your Mini Radio Pocket SI4735 experience! The new firmware adds EiBi transmitter data and an eco-friendly power-saving mode for longer listening sessions.
Can’t fit a full-sized 80-meter dipole in your backyard? Or maybe you’re tired of the high noise floor of a vertical? It’s time to look at the Half-Loop. This “open-loop” design provides a fantastic balance between the quiet reception of a loop and the simplicity of a wire antenna.
In this project, we explore a multiband Half-Loop configuration that covers everything from 80 meters down to 15 meters. We’ll discuss the radiation pattern, the importance of a good ground or counterpoise, and how to use a simple tuner to jump between bands. If you’re looking for a “stealthy” antenna that punches above its weight on the low bands, this build is for you. Let’s get that wire in the air!
The ATS Mini series represents one of the most innovative developments in pocket-sized DSP receivers for shortwave enthusiasts and ham radio operators. Built around the Silicon Labs SI4732 DSP chip and ESP32 microcontroller, these tiny radios pack remarkable functionality into an incredibly compact form factor. Let’s explore the technical evolution across all versions, from the original V1 to the latest V4. Built around the Si4732 chip and powered by an ESP32, each iteration has addressed hardware bottlenecks, from audio quality to RF interference
The 2N7000 regenerative receiver is a classic single-transistor radio that combines simplicity with surprisingly high sensitivity. By using controlled positive feedback, the circuit operates just below oscillation, dramatically increasing gain and selectivity.