The Army Receiving valve AR is fitted to the 'old interservice base' also known as I/S4. The anode and grid are brought out to opposite sides to give maximum separation and minimum interaction between input and output circuits. The small diameter tube and reduced height compared to the DER and similar.
It is believed that the AR was very similar to the M-OV DER but this military valve was made by several of the valve companies.
The triode is formed within a cylindrical anode and the filament is a single strand of thoriated tungsten wire.
The base showing the grid connection.
The base showing the anode stud.
The base seen from directly underneath showing the filament pins.
One of our exhibits and the etched lettering identifying the manufacturer as M-OV and GEC.
The other of our exhibits and the etched lettering identifying the manufacturer as M-OV and GEC.
The thin glass tube envelope is 23 mm in diameter, and excluding the I/S4 base pins is 80 mm tall.
References: 1003 Type A.R. was first introduced in 1922.