GexuliQardeno

GexuliQardeno is a design workbench for battery-free crystal radios that fits in your pocket. It calculates the LC tuning frequency, the inductance of a single-layer coil using Wheeler's formula, the wavelength and the length of a quarter-wave antenna, as well as the amount of copper wire needed and the matching of the earphone. • Tuning: f = 1/(2π√LC) by adjusting the capacitor value; you also see the wavelength. • Coil: radius, length and number of turns give the inductance in microhenries. • Wave and antenna: calculates the wavelength and the quarter-wave length of wire. • Winding: based on the number of turns and radius, the enamelled copper wire required and the wire diameter by AWG class. • Detector and earphone: matching a germanium diode and a high-impedance earphone. • Build steps, medium wave range 530–1700 kHz, materials list and a shareable build guide. The app suits radio enthusiasts, students and experimenters. The signal itself uses the earphone — no battery is needed. All calculations happen on your device without an account or login.