[CW] Crystal Amplification and Magnetic Amplification

[Alfred Lorona]

In March of 1920, a G. W. Pickard, of the Wireless Specialty Apparatus 
Company, described the oscillating crystal detector that made heterodyne 
reception of cw signals possible. The G may have stood for the name 
Greenleaf. Much earlier, Greenleaf Pickard was the inventor, and for which 
he filed a patent, of the familiar galena crystal detector with the moveable 
metal spring wound 'catwisker' probe with which most of us old timers are 
familiar when building crystal sets in our childhood/youth. Maximum DC 
voltage applied to the crystal was 9 VDC and adjusted by a rheostat.

In the early 20's, several researchers were developing detectors which were 
the forerunners of the FET device. But these were not the simple amplifying 
crystals as was Pickards invention.

No, I never tried the oscillating crystal thingie. It should be simple 
enough to try by someone that has a crystal set knocking about.

73, AL