[BC] Te st Your Wits on This

[Milton Holladay]

Well, it seems that I may have been correct when I suggested that it might be something simple yet subtle.
I'm about 50% convinced that it was the orientation of the contact ring rather than something incidental to moving it.

In some xmtrs, it may be possible for the concentric contact  rings to be mis-aligned off center so that they  do not make contact all the way around the tube such that squirrelley things occur such as your problem, though I think that is unlikely in the BE.   However, this may explain the wierdness that Richard described in a BTF-20 where rotating the tube cured a problem.  In the BTFs, when reassembling the socket, it is wise to assemble it loosely, insert the tube to align and center the contact rings, then tighten down with the tube in place to the greatest extent possible. The tightness of the nuts holding down the screen bypass capacitors will affect stability and, if loose, would be affected by the contact alignment and insertion of the tube..................
M