DIY Super Simple Sensitive Metal Detector
https://maker.pro/analog/projects/diy-super-simple-sensitive-metal-detector
Extremely simple Metal Detector whose making requires only one cheap integrated circuit TL084.
DIY Very simple Arduino Metal Detector
https://maker.pro/arduino/projects/diy-very-simple-arduino-metal-detector
Despite its simplicity, it has a relatively good sensitivity and perfect stability during operation
DIY Simple Alpha Radiation Spark Detector (High Voltage)
https://maker.pro/analog/projects/diy-simple-alpha-radiation-spark-detector-high-voltage
A very simple device that can detect Alpha radiation and the presence of Alpha radiation is manifested by small sparks between electrodes
DIY Simple Arduino EMF (electromagnetic field) Detector
https://maker.pro/arduino/projects/diy-simple-arduino-emf-electromagnetic-field-detector
The emf detector described in this video has a minimal number of components, which means that it is simple to make, and does not require any tuning. It works great right from the first power on.
DIY Simple FFT Spectrum Analyzer on 16x16 LED Matrix
https://maker.pro/arduino/projects/diy-simple-fft-spectrum-analyzer-on-16x16-led-matrix-1
Visually beautiful spectrum analyzer that can also function as an Audio VU Meter and Waterfall Analyzer.
DIY Simple BME280 Arduino Weather Station
https://maker.pro/arduino/projects/diy-simple-bme280-arduino-weather-station
Super simple Weather station containing only two components.
DIY Simple PCL82 Low Voltage (12V) Tube Amplifier
https://maker.pro/analog/projects/diy-simple-pcl82-low-voltage-12v-tube-amplifier
How to make a very simple single tube amplifier that also works at low voltage and is powered by 12V DC. Also, instead of an output audio transformer, a standard 220V/6V mains transformer is used.
DIY simple GU81 Tube Hybrid Amplifier (130 watts RMS in A class)
https://maker.pro/analog/projects/diy-simple-gu81-tube-hybrid-amplifier-130-watts-rms-in-a-class
The amplifier described in this project is "Hybrid", but now the case is reversed and the Tube is used at the output, thus preserving all the positive features of a pure Tube Amplifier.
DIY simple Arduino 24/7 Lightning monitoring system with graph and data logging
https://maker.pro/arduino/projects/diy-simple-arduino-247-lightning-monitoring-system-with-graph-and-data-logging
Simple to build, but powerful system for continuous monitoring of electrical discharges (lightning)