When Weschler started in 1941, panel meters were hand-made analog instruments. The typical meter had either a metal or bakelite case, a glass lens and an electro-mechanical movement. There were many US manufacturers during the 1940s and 1950s, including Triplett, Simpson, Weston, GE, Westinghouse, Beede, Hoyt, Hickok, Jewell, Marion, Supreme, and EMICO. Meters for DCV, DCA, ACV, ACA, and line frequency were standard.
