Steve,
I have used the umbrella configuration for about a year now both in EI and
G.
The one I used in EI had elevated radials, and an elevated feedpoint. The
vertical element was tilted about 15 degrees off vertical, but did well.
Now, back home in G Land, I am using a vertical.
It goes up 16 metres, and has 12m drooping radials at the top, at 90 degrees
to each other. It works against a ground of 70 radials, varying in length
from 7 to 15 metres, buried about 75mm into fair earth. My QTH is on the
top of a small hill, and I think that helps a bit.
I find that it is a bit noisy on receive, but seems to do well on long haul.
The NEC programme shows a good lobe at 15 degrees, and the antenna seems to
work just as modelled.
Here in Buenos Aires, I am constructing a double sized G5RV in a sloper
configuration from the top of the 15 floor apartment building....the normal
sized G5RV is doing well in that configuration on 80 through 40.
73 and good luck
Bob G4VGO EI7IU LU/KY0C
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