Audion_BTH-doubleW

This is a twin anode and grid type with wire leads, usually referred to as "double wing" in the U. S. It is an exact copy of the de Forest "double wing" Audion. An interesting observation about the origins of the tube is that these may have been imported from the US and rebranded before BTH had perfected their own tubes. This would explain the BTH logo on the tube.