Perhaps the simplest radio one can build is the crystal radio. Using a diode as a detector, the design generally uses less than 10 components and no battery, getting its power to run from the radio ...

Dark matter remains one of science's greatest mysteries, possibly making up 85% of all matter in the universe. Despite decades of research, its exact nature is unknown. One leading candidate to ...

Marked: "Marconi's Wireless Telegraph Co., Ltd. / No. 180014 - London." Instrument is designed to receive code signals in the wavelength range of 200-2500 meters. Aerial tuning inductance normally ...

Stamped: "Detector / Type A / No. W145 / DR. No. RW 50 A 133 A / W.N.Y. 1916". A three turret crystal detector with a 4-position sweep switch, two connecting screws ...