On 25 Oct 2013 at 4:32, Mike Everette wrote: > An interesting and largely forgotten "sweep tube" is the 807. > > In its octal-based "consumer" version it's known as the 6BG6. Yes. I grabbed quite a few some years ago. They ARE an octal-based 807 ! I think I paid something like $0.10 each for them then. I got about a dozen. Ken W7EKB