CPI International, Inc.
is the holding company for Communications & Power Industries
, the largest manufacturer and rebuilder of electron devices (primarily vacuum tubes
) in the United States
. C&PI was founded in 1995
when Varian Associates
sold its electron-device business to concentrate on medical systems. Its major subsidiaries include Eimac
(which manufactures new vacuum tubes for the broadcasting, radar, medical systems, and other applications), Econco (a vacuum-tube rebuilder), and Beverly Microwave Systems. CPI International made its initial public offering
in April, 2006.