Ronald C Armstrong

US Patent:

44729944, Sep 25, 1984

Filed:

Jul 18, 1979

Appl. No.:

6/058750

Inventors:

Ronald S. Armstrong - San Francisco CA

International Classification:

G10H 318

US Classification:

84 115

Abstract:

An improved electromagnetic pickup for a stringed musical instrument includes constant magnetic field providing magnets for each of the strings adjustably aligned adjacent to each of the strings at a sound providing region of a frame of the instrument. The aligned magnets generate a magnetic flux strength and orientation for each string tailored to the particular string and its tonal characteristics. A very high frequency preamplifier subsystem having a very low impedance input is connected to the strings through shielded connectors extending to the string anchors and functions to amplify greatly the minute electrical signals induced in the plurality of strings as they vibrate when the instrument is being played.

US Patent:

49282948, May 22, 1990

Filed:

Mar 24, 1989

Appl. No.:

7/330348

Inventors:

Warren T. Beard - Upper Marlboro MD
Ronald W. Armstrong - Edgewater MD

Assignee:

U.S. Government as represented by the Director, National Security Agency - Fort George G. Meade MD

International Classification:

G01N 2320

US Classification:

378 74

Abstract:

An improved asymmetric crystal topography x-ray imaging system employing a ine focus horizontal line source of x-rays and a crystal monochromator used in a compression mode. Relatively large horizontal and vertical dimensions of the monochromating crystal allow imaging of larger areas of imperfect crystals than previously possible, without adversely affecting image resolution. The high resolution two-dimensional images are a direct consequence of our method of controlling the probe beam divergences. An appreciably enhanced and useful intensity of monochromatic x-rays is obtained over that available with prior asymmetric crystal topography systems.