The 8255 or E88C is a tiny triode that was purpose designed for use in UHF television tuners. The UHF television bands rise to 900 MHz and with weak signals the RF amplifier had to have as low a noise figure as possible. The RF amplifier would be used at a high anode current to reduce the noise figure, hence the maximum anode current of 12.5 mA.
This view shows the frame grid behind the second 8 of 88. It is just a light grey with no detail.
This view shows the flay bottom U channel anode on the right. The valve is single sided.
Looking into the back of the anode.
This image shows the uncoated reverse of the cathode with the frame-grid wires across it. Between the cathode and the right hand grid support is a grey band that is the face of the anode of this planar triode.
Photomicrograph of the frame-grid taken through the envelope. The central structure is the reverse of the cathode tube.
The grid wires as they pass over a support rod. The cathode is at the base of the image.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 46 mm tall.