A couple more good reads:
http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/Vee/YagiModel.htm
http://www.w8ji.com/nvis_n_v_i_s_antenna.htm
In the first article above, W8WWV found the maximum vertical gain with a
dipole 1/2 wavelength above the ground with a reflector wire 39 feet
down from the antenna. Too bad as most of us can't even consider a
dipole 131 feet off of the ground!
73, Darrell VE7IU
On 16-07-18 02:28 PM, Jim Brown wrote:
RIGHT!
The usefulness of very low antennas for short distance work is a MYTH.
Slide 19 in this link shows that an 80M dipole produces maximum
radiation at high angles (70 degrees) at 60 ft, and that raising it to
90 feet loses only about 1 dB at high angles.
http://k9yc.com/VertOrHorizontal-Slides.pdf
I won't question that the very low antenna described might be quieter
than a high one -- in any given QTH it may be, but it is a LOUSY TX
antenna for ANY distance or angle.
73, Jim K9YC
On Mon,7/18/2016 1:26 PM, Darrell Bellerive wrote:
That may work well for receiving, but for transmitting the ground
losses at such a low height would be substantial. QRP with 100 watts.
:-)
73, Darrell VE7IU
On 16-07-18 01:08 PM, Stuart Rohre wrote:
Working at 1/8 wave above soil, brings as signal to noise gain, in
that "skip static" from Summer thunderstorms is greatly attenuated
or not picked up at all.
NVIS brought back 80m to usefulness for Field Days due to the
reduced noise floor when the antenna was 5 to 6 feet off ground with
a reflector at grass top level. (after mowing).
-Stuart Rohre
K5KVH
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Darrell Bellerive
VE7IU
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