On 1/17/2019 2:59 PM, Keith Dutson wrote:
I guess I should have said NVIS rather than cloud warmer. Used a 40 meter
dipole at 30 feet to work a lot of stations in US from YN2 a couple of years
ago.
This is another serious misconception caused by the way ARRL plots
vertical radiation patterns, setting the scale to the angle of maximum
radiation. If you plot patterns for all antenna heights on the same
scale, you learn that, in general, higher is better for NVIS, and, over
"flatland", for DX too.
http://k9yc.com/AntennaPlanning.pdf shows that 0.2 wavelength is
approximately optimum height for horizontal antennas for NVIS, and that
height has to be increased a lot to degrade NVIS. It also shows that
verticals are lousy for NVIS because they have very little radiation at
high angles.
I STRONGLY agree with KQ2M regarding the importance of terrain, and you
don't have to be on a mountaintop for it to matter a LOT.
73, Jim K9YC
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