Dave wrote:

I just found several 829B tubes - believe it or not in my garage...

So can someone tell me what they would have been used for?
Something tells me they're a VHF power tube.

You've gotten some good responses from some others in the NG.
The most unusual application for the 829B that I saw was their
being used to drive the magnetic-core memory modules in the
Whirlwind I computer racks on display in the Computer Museum
in Boston. The sockets may have originally been designed for
832's and "upgraded" to 829's for more drive or longer life.

Jim Bromley, K7JEB
Glendale, AZ