After re-reading the manual (and an hour or two of net surfing) it turns
out the reference frequency is tweakable via the TT remote command set.
More than ample adjustment to get it spot on.


(...I really have to learn to not read manuals when I'm over-tired. It
was there in a table. No reference to the feature in the manual, but it
was listed as a command none the less...)

Thanks to all who read my original post.

Pat