Medium-Mu Triode
The 27 Vacuum tube is a glass type used as a voltage
amplifier or detector in AC-operated receivers. It was
first developed by RCA in 1937 and requires a
five-contact socket.
Electrical Data
Heater Voltage ................................ 2.5 V
Heater Current ................................ 1.75 A
Preferred Substitutes ..... 27, 227, 227E, 57T227, A245, AX227, C227, C245, C-427, CX345,
D227, DE-1, ER227, EY227, GSY227, GY227, LS227, NU-27, P227_USA, SLY227, T27, UY227,
UY-227_Japan, Y227, Y227AC.
Substitutes ... 56