The 6GU7 was designed for use in the matrixing circuits of colour TV receivers. It is said to also be useful in phase inverter, multivibrator circuits and as a general purpose amplifier.
The Admiral name. The anode is much longer than most double triodes. The control grid supports are made of copper but unlike our other 6GU7 from Admiral they have no cooling fins.
The user is requested to remain loyal to the brand.
The thin glass tube envelope is 21 mm in diameter, and excluding the B9A base pins is 47 mm tall.
Reference: Data-sheet. Type 6GU7 was first introduced in 1963. See also1963 adverts.