Couple of Russian "big boys"
Posted: Sat Aug 20, 2016 7:50 pm
I believe that these are pulse-modulator tetrodes, not useful for audio. Second one is GMI-2B.
GMI-2B: https://frank.pocnet.net/sheets/018/g/GMI2B.pdf
GMI-2B: https://frank.pocnet.net/sheets/018/g/GMI2B.pdf