WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
EDIT: I just found out the VT-76 also exists as type 76 from RCA, unfortunately I can't seem to find much detail about it other than that it is a medium-u triode.