Electron tube 6F7 (6Ф7) is an old russian triode-pentode. Application: voltage amplification. It is basically russian version of the western tubes 6F7, VT-70 and CV1915, but it is not a direct replacement. Russian 6F7 has a different base (octal). New old stock tubes. Made in the early 60's. Manufacturer: Melz, Moscow.