The UCL83 is an AF amplifier triode and an output pentode combined in a single envelope. The use would have been for post detector amplification and loudspeaker driving in broadcast receivers and small VHF televisions sets. The 100 mA heater is for use on heater chains in universal AC or DC mains equipment.
The pentode on the left has all three wire grids visible. The triode on the left shows a single grid.
The construction features double mica discs. This is normally employed to reduce the effects of vibration.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 48 mm tall.
References: Data-sheet & 1040. Type UCL83 was first introduced in 1955. See also1955 adverts.
