The PCL84 is a television triode and output pentode mainly for use as a video output stage. For this wideband amplifier service a high mutual conductance is required and here the gm is 9.5 mA/V
The triode on the left and the pentode at right angles to it on the right. It can be seen to be a true pentode by the three grid support rods extending beyond the mica supports.
The pentode anode holes reveal the suppressor grid support. The wording is Made in England.
The thin glass tube envelope is 20 mm in diameter and excluding the B9A base pins it is 59 mm tall.
