DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
Explore DIY electronics and ham radio projects covering RF circuits, antenna builds, transmitters, audio tools, and radio experimentation
Harnessing solar power to charge lithium-ion batteries is not only energy-efficient but also an eco-conscious choice for portable electronics. In this article, we explore a compact and reliable lithium-ion solar charger circuit that uses a few standard ICs: LM2941, LM3420-8.4, and LMC662. Designed for charging a 2-cell Li-ion battery pack, this setup is ideal for […]
If your receiver needs a higher level of signal across the entire matching network, this signal booster circuit can furnish the solution. This Signal booster circuit, built around a few transistors and support components, offers an RF gain of about 12 to 18 dB from about 100 kHz to over 30 MHz
Radio frequency work can be tricky business, especially when you need to measure signal strength without the complexity of tuned circuits. Enter the untuned field strength meter (FSM) a simple effective tool that every electronics enthusiast should have in their toolkit.
Ham Radio Repeater Toneburst Module generates a precise 1750Hz toneburst lasting 0.5 seconds, essential for accessing UK and European amateur radio repeaters.
This audible continuity tester uses a simple oscillator IC to generate a tone when a closed circuit is detected. Powered by a 1.5V battery, it provides instant audio feedback for testing wires, fuses, PCB traces, and connections, making troubleshooting faster and hands-free.
Simple Crystal tester – The idea for this crystal tester circuit sprung out of the need of testing a large number of oscillator crystals lying unused in a big hobby box. testing the crystals one by one without the appropriate device would have been very slow and a time consuming task. Commercial crystal testers are […]
This is a clever Battery low power indicator circuit designed by G3AGX that provides a visual indication when equipment is drawing power, even at very low current levels. The circuit is particularly useful for monitoring standby power consumption or confirming that equipment is actually powered on. Battery Low Power Indicator Circuit Analysis The heart of […]