Supreme Instruments was formed in 1926 in Greenwood Mississippi by Jewell R. Williams that owned the company until the 1930's. In those early years, Supreme designed and produced many of the radio analyzers, multimeters, and tube testers used by radio repair shops and radio service men.

B.F. Dulweber took over the company in the 1930's when founder Williams left. He was assisted at Supreme Instruments by his son D.N. Dulweber. B.F. Dulweber was the owner of the "Kratzer Cured Lumber Company" from 1925 to 1929 in Dulweber (MS). The engineering staff at Supreme in the early 1930's were Vivion A. Johnson and Floyd Fausett. They each applied for and held several patents.
In 1938 E. G. (Grady) took over the engineering staff.
In 1947 Grady purchased Supreme Instruments. Supreme did not use production line methods to manufacture equipment. Each unit was assembled from start to finish by one worker. A signature of the Supreme employee that assembled the tester can often be found inside the case. Production line techeniques were not implemented at Supreme until World War II when war needs dictated a higher production rate.

During the war Supreme stepped up production and produced over 1500 panel meters a day. Over 200 units per day of the model 542 volt-ohm meter were also manufactured for the war effort.
In 1956 Hickok purchased Supreme Instruments Corp. The Hickok Inc-Supreme Electronics Div. still exists today in Greenwood Mississippi and manufactures automobile test equipment. (Information from Steve Johnson's Supreme Instruments Collection).