Sharp-Cutoff Tetrode
Blue Glass Balloon Globe
The Arcturus 124A Vacuum tube is a blue glass Balloon / globe
type used as an RF
amplifier or biased detector in AC-operated receivers.
It was first developed in 1930
by RCA and requires a five-contact socket.
Electrical Data:
Filament Voltage .............................. 2.5 V
Filament Current .............................. 1.75 A
Preferred Substitutes ................... 24, 124,
224, UX-224A, 324, CX-324A, 35, 51.