DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
Discover the Curumim Transceiver, an ultra-minimalist QRP CW rig for 7.030 MHz that combines a single-transistor crystal oscillator and LM386 audio amplifier into one of the world’s smallest working HF transceivers, ideal for homebrewers, educators, and portable CW enthusiasts
Quarter-wave COCO antenna design for 2 m band: stacked λ/4 coax elements with phase-reversing joins for compact high-gain VHF performance and easy DIY construction
Build a compact dual-band FBK sleeve antenna for VHF/UHF bands from coax cable. Simple, efficient, and ideal for portable ham radio use.
The ATS Mini receiver has long been a favorite among hobbyists and Shortwave Listeners (SWLs) for packing incredible functionality into a tiny, portable package. Now, the latest iteration, the ATS Mini V4, arrives on the scene, building on the success of its predecessors (V1, V3, and V3S) with significant enhancements that cement its status as a top-tier micro-controlled radio.
From Car Dash to SDR Lab: Turning the NXP TEF6686 Car-Radio Chip into a Versatile Multiband Receiver There’s a certain magic in hearing distant AM or FM stations fade in from the noise — a reminder of how much can be done with clever design and a bit of curiosity. Recently, hobbyists have discovered that […]
From the smallest Wi-Fi chip antenna to the largest High-Frequency (HF) wire arrays, radio antennas are the crucial link between your radio and the airwaves. They are marvels of physics, yet decades of folklore have created persistent myths that trip up even seasoned operators.
Shortened G5RV antenna design: a compact multiband HF dipole covering 20m–6m bands with ladder-line matching and 4:1 balun for portable or small-yard installs.
Learn to build a 145 MHz/433 MHz collinear antenna with 0.64λ radiators, 0.25λ phasing stub, and direct 50 Ω feed for compact high-gain VHF/UHF stations
Build the Popovic dual band antenna for 2m and 70cm bands — a simple, efficient DIY VHF/UHF antenna with excellent SWR, omnidirectional pattern, and easy home construction
Pocket SI4735 Dual Core Decoder firmware upgrade adds 400 kHz waterfall, improved SSB/CW/RTTY decoding, and faster scanning — transforming the ATS Mini into a powerful DSP pocket receiver.