Digital TV

[Bob DeMattia]

It is likely plain old multipath.  In additional to the direct path
you've probably got some pretty
strong reflections off the buildings in downtown Boston, the Blue
Hills, and the Waltham hills,
or planes flying overhead.   I don't recall you saying what type of
antenna you are using, but
it should be as directional as possible.  Also, all digital tuners are
not equal.  The echo-cancelling
algorithms are CPU intensive.  At the time the gen-1 models were made,
the technology required
to implement the more advanced algorithms of today was simply not
there (from a practical
standpoint).  I imagine some of the cheap designs out there now may
still be a generation or
two back.

-Bob