The E1R/N is essentially an ECH3 is a triode hexode mixer for broadcast receiver use but with different base connections. The base is the continental side contact type. The oscillator triode has to supply 11 Volts peak to peak for the hexode mixer for correct operation.
The Italian WWII Ministry of Finance label. This valve was aimed at military equipment.
The right side of the paper label give the date of 14 April 1941.
The centre of the label.
The classic envelope is 35 mm in diameter and, excluding the Ct8 base pins, is 88 mm tall.
References: Datasheet, 1040 & 1043. Type E1R/N was first introduced in 1940.