The PC88 is a UHF triode designed for the front end RF amplifier in Band IV and Band V television tuners. It is designed as a UHF frame-grid grounded grid amplifier.
The anode is an open ended box - seen here on the left. On the right is an open frame to balance the mica discs.
Here the anode box is on the right. The two grid supports are strapped together top and bottom to maintain the tension of the fine grid wire. At full size the grid winding looks to be a pale grey tone.
This image is looking directly at the grid wires and the uncoated side of the cathode.
The thin glass tube envelope is 21 mm in diameter and, excluding the B9A base pins, is 41 mm tall.
References: Data-sheet & 1040. Type PC88 was first introduced in 1962. See also1962 adverts.
