>From last years discussion of this topic (just about this time):
A properly rigged block & tackle system will reduce gin pole loads (or increase
safety margins) as long as the load does not wander "too far" away from the
There is a little bit of info, at the URL's below, that might be useful to those
interested in the subject.
I personally prefer getting a mast inside the tower before it grows too tall, if
that option exists.
73, Kurt, K7NV