The MR1 is a half wave rectifier with a 200 Watt anode dissipation. It was first made in 1919.
This type of rectifier was used in the 2MT (two emma toc) transmitter that made the first UK broadcast transmissions in 1922.
The complete valve and flying leads. The anode is clamped around a re-entrant tube - seen on the right.
Unusually this exhibit has an EMI makers logo. The filament connections are at the top of the image.
The filament tension spring is fixed into the complicated glass tube arrangement on the left. The anode connection passes through a side tube, seen here at the top left.
The balloon envelope is 101 mm in diameter, and excluding the base wires is 180 mm tall.
Reference: 1005. Type MR1 was first introduced in 1919. See also1919 adverts.
