sounds like an OLD 'voice call' like ctcss, A50 can be digit code.
al
wrote in message
ps.com...
I'm trying to identify some (tubes?) I got in a old beat-up piece of
equipment, and I would appreciate any leads. They have an octal base, a
grey metal envelope about 2" high, and are heavy as lead. The
manufacturer is "Voycall", and they are labeled "A50"
Anyone have any idea what these are?