AN/URM-25 signal generator

The AN/URM-25 signal generator was an electronic vacuum-tube radio-frequency (RF) signal generator used during the 1950s and 1960s by the U.S. Military to test electronic equipment. In accordance with the Joint Electronics Type Designation System (JETDS), the "AN/URM-25" designation represents the 25th design of an Army-Navy electronic device for general utility radio maintenance system.