At 10:36 AM 7/8/02 -0400, Guy Olinger, K2AV wrote:
>In urban areas, I've always found quite higher reception of man-made
>noise on verticals, for what ever reason. And unless the vertical is
>over an extended flat copper roof (block of same height row houses),
>practically speaking there's 3 db gone at those touted low angles
>right off the bat, to loss from ground absorption and clutter in most
>situations.
Not to mention the ~6 dB of ground reflection gain, though I grant you it
is apt to be at a pretty high takeoff angle unless the dipole is quite
high. Still, the lower half of the first lobe can extend pretty far down
toward the horizon before it is 6 dB below the nose of the lobe.
Another related question -- I picked up an HF9V vertical to experiment
with for minimal SO2R use. I have a 40 x 30 foot nearly-flat galvanized
steel roof on my garage, and am thinking about placing the antenna in the
middle of it with the antenna's ground lead connected to the roof. I
believe the sections of the roof are fairly well connected together, and
wonder what sort of performance it is reasonable to expect from it.
73, Pete N4ZR
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