The KTZ63 RF amplifier pentode, equivalent to a 6J7G was also noted as a low noise audio pre-amplifier.
The Osram brand label. The M-OV etched identification can be seen in the main image.
Due to the top screening, little can be seen of the internal structure. The control grid support is fitted with a side strut that connects to the wire from the top cap.
The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 106 mm tall.
References: Data-sheet & 1043. Type KTZ63 was first introduced in 1937. See also1937 adverts.
