MH4 Catkin metal Marconi Osram external anode audio output valve

Description

Marconi Osram MO-V MH4 Catkin external anode audio output valve was the first valve in the world to be in a metal envelope. Heavy and well made! Labeled MH4K other than that is it identical to the MH4. The catkin were expensive to make. Production lasted few years only.

The Marconi Osram MH4 is an indirectly heated triode. It is a high efficiency general -purpose valve for use as detector or  low frequency amplifier .

For sale most of MH4 variations.