DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
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.
Build a 5/4-wave VHF antenna for 145 MHz using 450 Ω ladder line and a choke feed. Shows how to mount, feed, and match this high-gain vertical for FM, repeater, and simplex operations on the 2 m band
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.
Build a broadband FM Bazooka (sleeve dipole) antenna for 88–108 MHz with low noise, stable impedance, and excellent wideband FM reception. Ideal for DX listening and clear stereo broadcast signals.
Build a Slim-Jim antenna optimized for 88–108 MHz FM broadcast reception. This ¾-wave vertical with integrated matching section delivers omnidirectional coverage, low noise pickup, and improved DX performance over simple dipoles or whips.
The Bazooka coaxial dipole is a broadband antenna using coax cable as both radiator and quarter-wave sleeve balun, naturally matching 50 Ω feedlines. This guide explains its design, operation, dimensions, and VHF/UHF scaling for efficient omnidirectional performance
Stacked 5/8-wave VHF Antenna for 2-meter band (146 MHz). Learn design theory, dimensions, tuning method, and original YY5RM reference for high gain ham radio