radhive 
Welcome back to our Electronics Basics series. In the first two lessons, we learned about electrons, electric charge, static charge, and electric current. Now we will explore three fundamental electrical quantities—voltage, current, and resistance—and see how they work together. We will use a water-pipe analogy to make the ideas easier to visualize. Like any analogy, … Read more
Introduction I got my first ham radio license in 2000, but it was 24 years later before I made my first satellite QSO with a U7V4 cross yagi mounted on my homemade AZ/EL antenna rotator. For years, I had known how much fun satellite operation could bring to a ham radio operator, but I never … Read more
Tired of Re-flashing Your ESP32 Just to Change WiFi or Fix a Web Page? If you have built any ESP32 or ESP8266 project with a web interface, you have felt this pain. You hardcode your WiFi credentials into the sketch, upload it, and everything works great until you need to change your WiFi credentials. Then … Read more
Disclosure: This is an independent introduction to SmartChamber-3D by maker ‘physton’. I am not the author of this project. The goal is to help makers decide whether it is worth studying, adapting, or building. Overview SmartChamber-3D is a chamber temperature control system for enclosed Bambu Lab P2S or P1S 3D printers. According to the OSHWHub … Read more
A More Efficient Antenna Is Needed for the Base Station To improve my Meshtastic base station’s ability to rebroadcast weak LoRa packets, I decided to replace the commercial “rubber ducky” coiled antenna with a homemade J-Pole antenna. While rubber ducky antennas are convenient for handheld devices, they are much less effective for a CLIENT_BASE node. … Read more
Ham Radio Tools SWR & Return Loss Calculator Convert between SWR, return loss, reflection coefficient, reflected power ratio, and mismatch loss. Add forward power when you want reflected watts and net power at the measurement point. SWR and reflected power diagram A transmitter sends forward power through a feedline to an antenna, with a smaller … Read more
Overview Have you ever wondered how far a UV band antenna could reach if it were mounted 1000 meters above the ground? It is a fascinating question for radio amateurs and technical hobbyists alike. Let us break down the science and look at what is practical in real operating conditions. First, 1000 meters is no … Read more
Disclosure: This is a review of the open-source project from maker TheLight, named “A Music Visualizer Clock.” It’s a small DIY desktop gadget that combines a digital clock, music visualizer, and environment sensor. The ultra-low power feature is the highlight of the project. We’re now sharing this handy maker project with electronics hobbyists around the … Read more
No WiFi? No Problem—ESP32 IoT Data Still Travels Far & Fast If you’ve tried to use an ESP32 IoT sensor in a remote area with no WiFi and Internet, you’ve probably run into the same problem. Maybe you want to check temperatures in a greenhouse, watch water levels in a distant pond, or record soil moisture over a … Read more
Electronics Tools Resistor Series / Parallel Calculator Calculate the equivalent resistance of two or more resistors connected in series or parallel. Add your resistor values, choose the connection type, and optionally enter a voltage to check current and power. Resistor network diagram Clean schematic drawings showing two resistors in series and two resistors in parallel. … Read more