Telefunken ECH83 triode heptode frequency changer (low voltage anode)

The ECH83 is a triode heptode frequency changer that has an unusually low anode voltage of 12.6 Volts, the voltage of vehicle batteries. This valve was clearly designed for use in such an environment, Mullard describes it as being designed for use as a mixer in hybrid car radios. The thin glass tube envelope is 20 mm in diameter and excluding the B9A base pins the valve is 59 mm tall. The ECH83 was first introduced in 1957.