General Radio Co 1950s Model 1551-A Sound Level Meter Shure 11"

Description

Vintage 1950's Sound Level Meter produced by the General Radio Company of Cambridge, Mass. Type No. 1551-A. Serial No. 952. Features non-directional crystal microphone by Shure Brothers of Chicago, IL / Model 9898 / Serial Number D4877 / Made in USA. Licensed under patents of the American Telephone and Telegraph Company. Calibrated 8/27/1970 by the Baynton Electronics Corporation of Philadelphia, PA.

"General Radio Company (later, GenRad) was a broad-line manufacturer of electronic test equipment in Massachusetts, U.S. from 1915 to 2001. On June 14, 1915, Melville Eastham and a small group of investors started General Radio Company in Cambridge, Massachusetts. During the 1950s, the company moved to West Concord, Massachusetts, where it became a major player in the automatic test equipment (ATE) business, manufacturing a line of testers for assembled printed circuit boards. It also produced extensive lines of electrical component measuring equipment, sound and vibration measurement and RLC standards. In 1975, the company name was changed to GenRad. In 1991, a startup QuadTech was founded as spinoff of GenRad's Instrumentation division and Precision Product lines, as well as the rights to use the "GenRad" and "General Radio" names. In 2000, IET Labs acquired from QuadTech the GenRad RLC standards, impedance decades, megohmmeters, digibridges, audio lines, stroboscope lines. Then in 2005 IET Labs purchased the Digibridge and Megohmmeter lines, which continue to be manufactured in West Roxbury, Massachusetts. In 2001, Teradyne acquired the GenRad board test system lines, which were relocated to Teradyne's corporate campus in North Reading, Massachusetts. Among General Radio's accomplishments over the years have been: The introduction of one of the world's first portable oscilloscopes. The production of many high-precision standards for inductance, resistance, and capacitance. The production of the stroboscope as the Strobotac. The production of the sound level meter. The Variac variable autotransformer, which was a U.S. trademark of General Radio from 1934 to 2001. Invention of the "five-way" binding post connector. Invention of the GR connector." (Source: Wikipedia)

Condition

Good Overall - Gentle wear commensurate with use/age

Dimensions

11" x 6" x 9" (Width x Depth x Height)