Early Radio Wave Detectors

acid adjustment aerial current alternating current apparatus Armorl arrangement audible battery BRANLY British Patent 18 capillary carrier caused circuit connected crystal current flowing decoherence deflection device diaphragm diode direct current disc dots ECCLES Edouard Branly effect Electrical Review Electrical World Electrician electrodes electrolytic detectors Fessenden filings coherer film Fleming flux frequency galvanometer glass tube Hertzian heterodyne History of radio hysteresis detector illustrated in Fig iron Lodge London loop magnetic field magnetisation Marconi mercury metal mounted movement needles operation oscillation oscillatory current particles Phys plate platinum Proc produced radio telegraphy rectifier Reference relay resistance rotating Science Abstracts Science Museum photograph search coil sensitive shown in Fig solenoid spark spark-gap specimen steel tantalum telegraphy and telephony telephone earpiece telephony Chapman telephony Longmans thermocouple thin ticker TOMMASINA transmitter types of detector valve vibration voltage wire wireless telegraphy Wireless World World and Engineer