The PV5DE is an dull emitter output triode that was introduced in 1924. Our envelope shape is different to that illustrated by Thrower.
The type one BBC stamp on this valve dates its manufacture to between November 1922 and September 1924. As the PV5DE was issued in 1924 this exhibit is clearly from an early batch.
Another view of the brass base and etched lettering. The base pins are of simple split construction.
The base lettering showing both dull emitter and the five volt rating. This was to be used with a six volt accumulator and a rheostat.
The Type designation lettering is not full on to the envelope but the P and V are clear as is the E. Under a glass the full PV5DE can be read.
The balloon envelope is 53 mm in diameter, and excluding the B4 base pins is 87 mm tall.
References: 1003 & 1004. Type PV5DE was first introduced in 1924. See also1924 adverts.
