6K8G RCA classic triode hexode frequency changer or mixer for broadcast applications

The 6K8G is the classic triode hexode frequency changer or mixer for broadcast applications. The exhibit has a clear glass bulb and would rely on external shielding where other mixers had external zinc paint sprayed on to provide screening. For isolation of the signal input and output circuits the hexode input grid is taken to the top cap.

The original design for the 6K8 was as a metal valve and the electrode structure is shown in that exhibit.

The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 98 mm tall.