The 6AC10 is a compactron triple triode designed for colour difference circuits in colour TV receivers. It has a defined warm-up time of 11 seconds.
The three triodes are identical high mu types and designed for Class A applications.
The GE logo. The heater connections look to be in series. Each anode is blackened to assist in heat dissipation. Each section has an anode dissipation of two Watts.
The end view of one stitched anode.
The identification is etched into the dome of the envelope.
The wide glass tube envelope is 29 mm in diameter, and excluding the B12C base pins is 47 mm tall.
Reference: Data-sheet. Type 6AC10 was first introduced in 1962. See also1962 adverts.