RCA's first version was an early octal base tubes, like most with this base having a metal, rather than glass, envelope.
Like most with this base it had a metal, rather than glass, envelope. RCA's first version was an early octal base tube.
RCA's first version was an early octal base tube. Like most with this base it had a metal, rather than glass, envelope.
RCA's first version was an early octal base tube. Like most with this base it had a metal, rather than glass, envelope.