CPC Subgroup
H03F 3/36 with tubes only
Full Title
Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements > DC amplifiers in which all stages are DC-coupled (H03F3/45 takes precedence) > with tubes only
H03F 3/36 Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements > DC amplifiers in which all stages are DC-coupled (H03F3/45 takes precedence) > with tubes only