This 12E1R is a magnificent device. Given the firm metal skirt and method of construction, it is very likely that this is a rugged version of the 12E1 series pass valve but we have no evidence to support this.
The oval anode and strap anode connection are clearly visible. A mica sheet at the top of the metal skirt hides the support structure.
The 12E1 is a power output valve for use as a series pass valve in stabilised power supplies. The heavy demands placed on valves used as control elements in regulator circuits makes it vital that the ratings are not exceeded.
The wide glass tube envelope is 36 mm in diameter and, excluding the IO base pins, is 119 mm tall. The skirt maximum diameter is 42 mm.
Absolute Maximum Operating Conditions¶
Updated January 18, 2013.