Marvin,
To make it short-n-sweet, no, it wouldn't be practical. The
'better than nothing' route sometimes isn't very much better
than nothing, and I think that's what you would have. If you've
got that 70 feet of tower/tree/whatever, why not hang an
inverted
'L' off of it? Ought to work much better, and depending on the
tuner, on all bands too.
'Doc