The ECL80 is a triode, output pentode for audio use. The heater at 6.3 Volts and 300 mA makes this valve suitable for equipment with mains transformers and heater chains across the domestic mains.
The ECL80 is a low power device with the triode feeding the pentode for a compact single end audio stage.
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 valve is branded Loyds, a name we have not seen before. Possibly LLoyds. The ECL80 is printed in a font that was used by Mullard and features a distinctive elongated shape on the C etc and tiny serifs. The guess is that this was made by Mullard.
The Small triode is mounted above the pentode and shares a common cathode that makes bias arrangements awkward.
The triode grid connection - on the left - is screened as it rises up the envelope.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 59 mm tall.
References: Data-sheet & 1040. Type ECL80 was first introduced in 1950. See also1950 adverts.
