coil antenna -
71Cat's-whisker detector — Galena cat s whisker detector Precision cat s whisker d …
72Power dividers and directional couplers — A 10 dB 1.7–2.2 GHz directional coupler. From left to right: input, coupled, isolated (terminated with a load), and transmitted port …
73Char D2 — Type Medium tank Place of origin …
74Colorado Springs Notes, 1899–1900 —   …
75Mainframe (G.I. Joe) — G.I. Joe character Mainframe as seen in the Sunbow G.I. Joe cartoon. Mainframe Affiliation G.I. Joe Specialty Communications …
76My Inventions: The Autobiography of Nikola Tesla —   …
77Low frequency — or LF refers to Radio Frequencies (RF) in the range of 30 kHz ndash;300 kHz. In Europe, and parts of Northern Africa and of Asia, part of the LF spectrum is used for AM broadcast service. In the western hemisphere, its main use is for aircraft… …
78Hearing aid — Behind the ear aid In the ear aid …
79Counterpoise (ground system) — A counterpoise is a type of electrical ground that is not connected to earth. It is used in radio antenna systems when a normal earth ground cannot be used because of high soil resistance[1] It consists of a network of wires or cables (or a metal …
80Antique radio — DIORA AGA RSZ 50 ca.1947 from Poland An antique radio is a radio receiving set that is collectible because of its age and rarity. Although collectors may differ on the cutoff dates, most would use 50 years old, or the pre World War II Era, for… …
