TR-Switch
The Bowmac Laboratories 1B40 Vacuum tube is also known as
a 2J1B40. It is a 1KW rated glass tube. The range is from
1075 to 1095 MHz with an external cavity. It has an
electrodeless discharge. This tube has the ground ring
and a keep-alive electrode connection in the base.
It was made by Bomac and Sylvania and measures 38x20mm
(12mm across glass).
Preferred Substitutes .........2J1B40, 164D