The CB215 is a double triode audio output valve from 1936. Like similar valves this was designed to offer reasonable volume at minimum consumption from dry cell HT batteries.
The CB215 was designed to provide up to 1.7 Watts of audio with an anode load of 10 kΩ.
The original CB215 on a B7 base dates to 1936. This exhibit was the 'S' variant of 1938 with the Ct8 side contact base.
Thanks to Mark Mallison for sending the image.
The classic envelope is mm in diameter, and excluding the Ct8 base pins, is mm tall.
Reference: 1043. Type CB215S was first introduced in 1938. See also 1938 adverts.
Absolute Maximum Operating Conditions¶
Updated January 05, 2022.