Hi Jan,
> Seems to me that anything much shorther then 4 wl doesn´t
> work. If you check Misek's book you can see that you need
> about 4 wl for 25-30 deg waveangle and anything higher than
> that is useless.
I don't follow that line of thought. Even a 1 WL Beverage has good
response along the ground for groundwave, and at low wave angles
for skywave.
A 4 WL Beverage is about useless because the phase of the
arriving wave randomly and rapidly changes in a few wavelengths of
distance.
It is virtually impossible to keep two points separated by more than
1 or 2 wavelengths "in-phase" because of the effects of
propagation. This is especially true at sunrise or sunset, when the
ionosphere is changing.
I've had 3 WL Beverages, and quickly found in A-B comparison to
shorter 1 and 1-1/2 wl Beverages they were generally worse....not
better. All my long Beverages are now long gone.
The few times the ionosphere is stable enough to allow antennas
spread over a large distance to be effective, I can combine a bunch
of smaller antennas into a large array from the operating position.
At least on 160 meters, the number of times a year I can use what
amounts to a 4 WL long array numbers in the single digits!
73, Tom W8JI
w8ji@contesting.com
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