John Passaneau wrote in news:hnqnnl$kk5a$1
@tr22n12.aset.psu.edu:

Can I cut the lower support leg down to 8 inches without a major
impact on the performance of the antenna?

The support leg is just that a leg. You can make it any length that
works for you.

The 'support leg' as it is being discussed in not just a physical support
for the half wave.

If the upper half wave section carries current, there must be a non zero
current at the lower end of it. That current MUST exist as a common mode
current on the upper part of the 'support leg' as the OP terms it and you
concur.

That common mode current is a standing wave, and the distribution of it
on the 'support leg', feedline, and any conducting supporting structure
makes all of these elements part of the radiating system to some extent,
depending on the actual geometry and their coupling to other conductors
in close proximity.

So to represent that U shaped section as merely supporting structure is
to deny how the thing really works... but then that is the stuff of J
Poles.

Owen