DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
“DIY” on DXR Electronics Bits is where practical ham radio projects come to life. Here you’ll find buildable circuits, antennas, receivers, preamps, audio tools, and experimental rigs designed for real‑world shack and field use. From compact HF antennas for small spaces to regenerative receivers, QRP transmitters, and uBITX add‑ons, each article focuses on parts you can actually source and solder on the bench.
Ditch the lossy traps and discover the Morgain Antenna—a clever, compact dual-band dipole for 40m and 80m. Operating at just 20 meters long, this wire-only design uses folded elements to achieve resonance without bulky coils. The ultimate space-saving solution for your HF station
Limited on space but want to get on 40m? Learn how to build a high-performance, reduced-size 40m antenna using high-Q loading coils. This guide covers calculations, coil winding, and tuning techniques to fit a 20-meter band antenna into a compact 10-meter footprint.
Low on space but want to reach the 80m band? This technical guide walks you through building a shortened Inverted V antenna for 3.700 MHz. Using high-inductance loading coils, you can fit a full 80m radiator into a restricted urban footprint while maintaining a low SWR
Build the legendary G5RV multiband antenna with this comprehensive DIY guide. Discover the technical balance between the 102ft radiator and the critical matching section that allows for 80m–10m operation. Learn how to optimize your feedline and avoid common RFI “growing pains”
Boost your VHF performance with the DIY 145 MHz Twin Delta Loop antenna. This technical guide explains how to construct a high-gain, bi-directional array using simple wire and a gamma match. Perfect for weak-signal 2-meter DX and satellite work without the bulk of a Yagi
Unlock extreme bandwidth with the UR0GT Broadband Avia Antenna (RW4HVN Mod). This technical guide explores the unique geometry that allows for seamless performance across Airband, 2m Ham, and Marine VHF without a tuner. The ultimate wideband solution for VHF explorers and monitoring enthusiasts.
A simple and effective 2-meter ham band sleeve dipole antenna design using a ¼-wave whip and a ¼-wave aluminium sleeve over copper braid.
DIY ESP32-S3 CYD 480×320 FM radio with SI4732 DSP and touchscreen tuning. High-resolution Arduino receiver project with scan and preset features.
Looking for an effective HF antenna for a high-rise or apartment balcony? This practical guide from VU3DXR details the construction and performance of a Loaded Loop Antenna—a compact, high-efficiency solution designed specifically for radio amateurs facing severe space constraints.
Mosquito TRX is a single-MOSFET 40 m CW transceiver for 7030 kHz using crystal control and direct-conversion reception — an ultra-simple QRP rig and SDR front-end for sound-card radios