200A VALVE AND 201A

Radio Record, Volume I, Issue 14, 21 October 1927, Page 3

200A VALVE AND 201A

The 200A type valve has a particular advantage over the 201A type when they are used as detectors. It has beet proven by Alexander Senanke, M.E., E.E., radio engineer for "Popular Science’? Institute of Standards that in detecting the very weakest signals the 200A type valve is three times more sensitive than the 201A type, and in detecting slightly less weak signals the 200A type ‘s eight times more efficient than the 201A type valve. On the very loudest signais, such as local broadcasting, the 201A type valve is, however, about one-twelfth more powerful than the 200A type. But it is onlv on the very loudest signals that tlie 201A type can compare with the 200A, for even when signals can be classed as halfway between very weak and very loud: the 200A type gives almost double the | volume as compared with the 201A type valve -" _aar