The 4Y35 ia a directly heated half wave rectifier on a three pin base and was made by Tekade (TKD) in Germany. Although much smaller, it has similar ratings to the Philips 1802.
The working volume is an oval cylinder with side flanges. Inside the filament is a pair on inverted Vs. The tension springs can be seen above the top mica.
The broad face of the anode.
The three pin base.
The thin glass tube envelope is 16 mm in diameter, and excluding the base pins is 67 mm tall.
Reference: 3002. Type 4Y35 was first introduced in 1930. See also1930 adverts.
