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.
Simple zener diode tester Ever found yourself with a handful of zener diodes, wondering if they’re still good or what their actual breakdown voltage is? Zener diodes are incredibly useful components for voltage regulation, but sometimes, their markings can be ambiguous, or you just need to quickly verify their functionality. That’s where a simple zener […]
Making printed circuit boards There are many ways to produce your own printed circuit boards. Small boards for DC switching circuits are easy to make because neither the size nor the shape of the copper foil traces is critical. Boards containing many digital ICs are considerably harder to lay out and etch. There are also […]
An NE567 tone decoder, tuned to the transceiver`s CW offset frequency, ensures that the transceiver will be transmitting on the same frequency as the received CW signal. Simply tune the transceiver so that the LED lights. Eight to 13 Vdc is required; this can be taken from the transceiver supply or an extra battery. Audio […]
DIY – 137 Mhz V-dipole antenna for weather satellites reception D.Prabakaran VU3DXR A V-dipole for NOAA weather satellites on 137 MHz has been published by 9A4QV and it seems to get very good results. The designed antenna works at frequency 137 Mhz with omnidirectional radiation pattern. The length of the each leg should include the […]
This white led torch circuit provides an effective solution for powering white LEDs. It is ideal for flashlights, emergency lighting, and various other applications. The circuit operates efficiently from one or two primary cell batteries. The core of the circuit involves a transistor (Q1) and a tapped inductor, forming a blocking oscillator. When the power […]
ubitx3 with nextion display Demo of ubitx3 with nextion display reception in my shack. The uBITX v3, developed by Farhan VU2ESE, serves as an excellent foundation for this upgrade. Built around the Arduino Nano platform, this QRP transceiver covers all HF amateur bands from 80 to 10 meters with approximately 10 watts output power. The […]