CPC Subgroup
H01J 21/26 with means for concentrating the electron stream
Full Title
Vacuum tubes (H01J25/00, H01J31/00 - H01J40/00, H01J43/00, H01J47/00, H01J49/00 take precedence; details of vacuum tubes H01J19/00) > Tubes with more than one discharge path; Multiple tubes, e.g. double diode, triode-hexode > with means for concentrating the electron stream