A very large, forced-air-cooled transmitting tetrode introduced in the 1960s. I have one Rare Mullard QY5-3000A transmiting tube.The Mullard QY5-3000A is.
A very large, forced-air-cooled transmitting tetrode introduced in the 1960s. I have one Rare Mullard QY5-3000A transmiting tube.The Mullard QY5-3000A is.