Alan Taylor wrote:
Roy, ruling out quad loops and multi element antennas what do we have
available? I like the idea of working both LP and SP to the US but if you
have an idea for a wire antenna supported by only two ropes I would consider
that. What would the pattern be like for a bobtail with extra vertical
elements spaced the usual half wave? With the trees I have in mind I could
possibly fit in six vertical elements.

Of course, what I'd recommend is that you model some of these antennas
with a program like EZNEC. The free demo program is adequate for some of
the antennas you're interested in. The demo program is able to model
some more complex arrays with quite an accurate pattern -- what suffers
is the accuracy of the reported feedpoint impedance.

One antenna you might consider is the "Field Day Special"
(http://eznec.com/Amateur/Articles/Fi...y_Special.pdf). It has two
elements, but can be suspended with two ropes by using spreaders made
from PVC pipe or other light weight material. The advantage to this
antenna over some others is that it has a unidirectional pattern which
is easily and instantly reversible. With a unidirectional pattern, you
get a broader beamwidth for a given amount of gain, compared to a
bidirectional array. It also reduces QRM off the back, but of course you
get more to the sides of the broadside direction since the beam is wider.

Roy Lewallen, W7EL