All,
Thanks all for the info. Basically, there's a whole myriad of
cards and monitors for DEC systems, and there's no single tube
that works with them all.
Solution (for me, ymmv) was to get a (cheap! :) multisync monitor
with BNC connectors and sync-on-green capability - I was able to
get a used Iiyama MF8117T (known to US people as IDEK MF8117T)
17" tube. Works like a charm, rock-solid picture on all systems
I could set up for testing. Neat!
I am typing this in a window on that thing, connected to the
VXT2000+ X Terminal, which in turn is connected to my OpenBSD
VAX (4100). Yay!
--fred