Sensibly equivalent¶ to:
Mullard describe the ECC91 as a double triode with a common cathode for use as an RF power amplifier or oscillator. They further state that an output power of 1 Watt may be obtained from an ECC91 in a push pull oscillator at 250 MHz. This would involve an anode voltage of 150 Volts and a common grid resistor of 2000 Ohms. Each valve would dissipate 1.5 Watts.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 48 mm tall.
References: Datasheet & 1040. Type ECC91 was first introduced in 1956.
Absolute Maximum Operating Conditions¶
PDF scanned from an original document held by the museum
Updated January 26, 2013. shape:thin.glass.tube construction:all.glass type:double.triode age:1950.1960 base:b7g heater:6.3v pins:7 pin:1.a(2) pin:2.a(1) pin:3.h pin:4.h pin:5.g(1) pin:6.g(2) pin:7.k