The 5J/180E is an RF power pentode with an external anode and fitted fins for forced air cooling. As a Class C power amplifier an output of 2.9 kW can be obtained across the HF region to 30 MHz.
The anode and cooling fins. The ceramic support for the six base pins has each pin function printed on it.
The six pin base.
The identification plate. Although branded ITT it was made in England by STC.
Thanks to Manori M Madurawala for supplying the image.
The balloon glass envelope is 92 mm in diameter and, including the base pins, is 220 mm tall.
Reference: Data-sheet. Type 5J/180E was first introduced in 1956. See also1956 adverts.