DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
If you are running a multiband doublet or any antenna with a tuner, ladder line will outperform coax on almost every band. Here is how to build your own from scratch — four proven designs, common materials, and every practical detail from spacer drilling to routing it through the shack wall.
The Baofeng UV-5R Mini brings USB-C charging and Bluetooth to the classic UV-5R platform. While it excels in portability, it faces significant hurdles in Airband reception and UI quirks.
Slow Scan Television is a method of transmitting still images over radio using audio frequency tones. The term “slow scan” distinguishes it from conventional fast-scan television (like broadcast TV), which requires much wider bandwidth.
The Reverse Beacon Network represents one of the most significant technological advances in amateur radio during the past two decades. By providing instant, objective feedback about your transmissions, the system empowers operators to understand their stations better, optimize their performance, and make informed decisions about when and where to operate. Whether you are testing a new antenna, chasing DX, competing in contests, or simply exploring the bands, the RBN adds a dimension of awareness that was previously impossible.
The Hotel Antenna is a clever space-saving vertical antenna design popular among VHF and UHF amateur radio operators. It is especially useful for radio amateurs living in apartments, hostels, or temporary locations where installing large outdoor antennas is not practical.
Operating on 80m, 40m, and 20m from a small backyard is no longer a challenge. Learn how to build a compact, loaded multiband HF dipole that uses precision-placed coils instead of traps. This high-efficiency design offers resonant performance on three major bands using a single 1:1 balun
Enter the NanoVNA Test jig Kit, a simple yet powerful “sea of holes” that transforms your VNA from an antenna analyzer into a full-scale laboratory tool for component characterization and RF circuit prototyping.
Build a 4:1 un-un impedance transformer to match end-fed wire antennas to 50 Ω coax. Ideal for long-wire, vertical, and off-center-fed antennas, improving SWR and RF transfer in multiband HF installations.
This article explains the construction, operation, and real-world usage of a 9:1 impedance transformer (UN-UN) for long wire and random wire antennas, making it ideal for SWL listeners and amateur radio operators.
The 3-Element Yagi antenna is a fantastic project for any radio amateur looking for a reliable, high-gain directional antenna that’s surprisingly straightforward to build.