Sensibly equivalent¶ to:
The ECL80 is a triode, output pentode for audio use. The heater rating is defined for both voltage and current so that parallel or series heater configurations are open to the designer.
Mullard describe the ECL80 as primarily designed for use in television receivers (VHF 405 line models) with the triode as a frame blocking oscillator and the pentode as a frame output valve. Other applications include the use of the triode as a line blocking oscillator, AF voltage amplifier or in multivibrator circuits and the operation of the pentode as an audio output valve or a synchronising pulse separator. This valve was also used in low cost record players with high output crystal pick-ups, normally with a metal rectifier. The latter being an early solid state device.
The ECL80 was not without faults in use and the above article gives details.
The ECL80 has a common cathode and so the triode can be mounted above the pentode. Here it can be seen above the top micaand set at 90 degrees to the pentode grid axis.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 58 mm tall.
References: Datasheet & 1040. Type ECL80 was first introduced in 1950.
Absolute Maximum Operating Conditions¶
Updated March 22, 2014.