The ECC85 is the definitive double triode for the front end stages of FM radio receivers. It was designed specifically for the purpose and released in 1954. This exhibit by Philips has ate Miniwatt brand name.
The two independent valves are screened by a rectangular plate across the diameter of the envelope. The screen extends beyond the area of the triode sections to offer the maximum screening between oscillator and mixer.
One box anode with side flanges for heat sinking and to allow stitching together of the thin sheet.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 48 mm tall.
References: Datasheet & 1040. Type ECC85 was first introduced in 1954.