The 6JS6C is a purpose designed television line output valve, or sweep tube. Like many other line output valves they also could be used for RF power amplifiers. The 6JS6C was used in designs from the early 1970s.
The Yaesu FT-101 used these valves for the final power output stage operating up to 30 MHz and far outside the manufacturers original specification.
The 12 base pins have a gap in the circle to act as a key as is common with most glass valves. The green band indicates a long life high quality valve.
The wide glass tube envelope is 35 mm in diameter, and excluding the base pins is 91 mm tall.
References: Data-sheet & 3002. Type 6JS6C was first introduced in 1968.
Absolute Maximum Operating Conditions¶
Updated May 03, 2014. shape:wide.glass.tube construction:all.glass type:pentode age:1960.1975 base:b12c heater:6.3v pins:12 pin:1.h pin:2.k pin:3.g2 pin:4.bp pin:5.g1 pin:6.- pin:7.ic pin:8.ic pin:9.ic pin:10.bp pin:11.g2 pin:12.h pin:tc.a