Single 8877, 4KV @ 45-55 watts drive, ~50 ohms at the socket pins. Single 3cx800a7, 2.2KV @ 25-30 watts drive, ~50 ohms at the socket pins. Paul PAUL HEWITT WD7S PRODUCTIONS QRO HOMEBREW COMPONENTS http://wd7s.home.att.net > Greetings, > > What's the GG cathode input > impedance for the 8877 and > the 3CX800A7? Can't > find my notes. > > Tks, > es 73 de Pete WA5JCI EM21jv >