[klemer]

Thank you Dale & Ron.
Very thorough analysis & reverse engineering, Ron!  Love it.
Glad I didn't even consider "just trying it".  Lesson learned years ago.
I have a good Simpson audio output meter, and can use that and normal signal generator hookups.  I just went down a "rabbit hole" since Philco said using their Alignment Adaptor and a VTVM (which I also have) was "a very sensitive indication of A.V.C. voltage". Now I wonder which is better.  I have a Loctal socket on the way here, that will make a better thru Loctal test adapter with pin-outs all around.  The one I had didn't survive teardown; I HATE epoxy (or equivalent) sometimes!  I like to make my own adapters, rather than buy one from eBray if possible. Will advise output vs A.V.C. voltage!
Thanks all!