The RK-1851 is an amplifier pentode designed for television and aimed at the amateur market. The control grid is taken to the top cap for maximum isolation between grid and anode circuits.
The use is in RF and IF stages.
The RK is a Raytheon prefix and generally the valve is known as 1851.
The top cap is smaller than standard and the valve comes complete with top cap spring connector.
As usual the valve is licensed for types of use.
The top cap and connector set in a paxolin sheet.
The International Octal base with pin position unused.
The thin metal tube envelope is 25 mm in diameter, and excluding the IO base pins is 66 mm tall.
References: Data-sheet & 3002. See also RK-1851 PDF file as well. Type RK-1851 was first introduced in 1938. See also1938 adverts.
