Audio Development Co.
2851 13th Ave, South, Minneapolis 7

ADC Telecommunications

Not to be confused with ADC Audio Dynamics Corporation.

ADC had a branch office in Germany at Auerfeldstr. 22, 8000 München 90 (unclear).

Founded in 1935 by Ralph Allison for the manufacture of the Audiometer. In 1937, he was joined by Walt Lehnert and the company's product line was diversified to inlcude amplifiers and transformers for the broadcast industry.

1942 saw the development of an audiosystem for the Univeristy of Minnesota. The resulting jacks, plugs, patch cords and jackfields layed the foundation for ADC's later entry into telecommunications.

The audiometer product line was sold in 1949 and in 1961 they merged with Magnetics Control Company, a manufacturer of power supplies and magnetic amplifiers, the company being renamed ADC Magnetic Controls.

By 1976 the company had become the largest independent supplier of test boards in the US. Growing success in the telecommunications businiss led to the sale of the magnetics business in 1984 and the name was changed to ADC Telecommunications.

During the 1990s, the firm diversified further and acquired diverse interests, resulting in the formation of numerous divisions. [1]

Following the dot.com crisis in the early 2000s, ADC was sold to Tyco Electronis (TE) in 2010. 5 years later, the broadband network solutions business unit of TE and with it the former ADC was sold to CommScope, formally marking an end to the company's existence. [2]

[1]  ITU Constitution and Convention Report, Nov. 13, 1997
[2] Wikipedia