Power Pentode
Various Name Brands
The 47 Vacuum tube is a glass type used in the audio
output stage of radio receivers.
It should be mounted in a vertical position. Horizontal
operation is permissible if pins 1 and 5 are in vertical
plane.
The '47 is a power amplifier pentode for USC in the audio
output stage of AC receivers. It is capable of giving
large power output with a relatively small input signal
voltage. In comparison with three-electrode power
amplifiers of the same plate dissipation, the '47 is
capable of greater power output with the additional
feature of higher amplification. This power-handling
ability of the '47 is made possible by the addition of
both a suppressor and a screen between the grid and
plate.
The 47 tube was first developed by RCA in 1930.
Electrical Data:
Heater Voltage ................................ 2.5 V
Heater Current ............................... 1.75 A
Preferred Substitutes.............................
247, 247S, 247-S, 447, 38047, A247, A-247, CV1772, EY647,
EY-647, F247, F-247, G47, G-47, NY247, NY-247, PH247,
PH-247, PZ, VT47, VT-47, UY47, UY-47, UY247, UY-247, UY247B,
UY-247B, Z47, Z-47.