The Universal triode from Myers is of double ended construction to reduce inter-electrode capacitances and was a successful product. This exhibit is of the earliest form of construction. It was also known as the RAC-3 and is a bright emitter. It was later superseded by the dull emitter Dry Battery valve.
The image shows the valve mounted on an ebonite base. This base does not have an address but carries the diamond Myers logo and is probably from the Canadian factory.
Original box, this time showing the New York address.
Thanks to Joe Gruber for sending the images.
The thin glass tube envelope is 16 mm in diameter, and including the base pins is 85 mm tall.
References: Joe Gruber, 1047 & 3002. Type Universal was first introduced in 1922.
Absolute Maximum Operating Conditions¶
-1 to -10
Updated November 26, 2020. shape:thin.glass.tube construction:pinch type:triode age:1920.1930 base: heater:4.0v pins:4 pin: