On Sat, 2008-06-07 at 11:10 -0500, Rob Atkinson wrote:
> <<<THIS is why antennas fed by open wire line tend to be noisier than those
> fed with coax. It isn't the line, it's the fact that you can't effectively
> choke it. >>>
>
> Hmmm, when I switch between my coax fed gap titan vertical and my 600
> ohm ladder line fed horizontal loop, the noise level is 5 S units
> higher on the gap vertical.
Many have alleged the vertical matches the polarization of noise. Part
of that may be true, also the quarter wave vertical usually has a low
radiation angle and equal sensitive in all directions. The loop may not
have such a low radiation angle or such an equal response in all
directions. But for working a few hundred miles on bands below 14 MHz,
an antenna wit mostly upward radiation will ignore local noises sources
yet its vertical radiation will bounce back off the appropriate layers
and give excellent coverage for a couple state range in all directions.
The vertical will not give that near local coverage, but its low
radiation angle will make it a big signal 1/4 or more the way around the
world, but it won't be heard much closer than that.
Each antenna type, horizontal loop, vertical, dipole and yagi array, has
its place and performs well for some path, but there's no path that all
these will work.
>
>
> 73,
>
> rob / k5uj
> _______________________________________________
73, Jerry, K0CQ
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