[Elecraft] Attic Antenna

[Rick Dettinger]

> I live in a restricted community and am thinking about putting a 20
> meter dipole in the attic. I know most of the issues with doing this but
> I don't know the effect the roofing material will have on my signal. The
> roof is 1/2 in thick cement tiles. Has anyone had experience with this
> setup?
>
> Thanks,
>
> Larry, KB5DXY
> K1 #2269
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The attenuation of any materal is a function of its thickness, measured in
wavelengths, as well as its electrical  properties.  This means that for a
given roof material, you will have less signal attenuation at 160 M then at
10 M.  This should be true for trees, rain or snow also.  This is why the US
Navy uses extreme  low frequencies to communicate with subs under water.
Like in the audio range, except its still radio.
I tried a 20 M. dipole in my wood framed attic before I hade an antenna
tuner.  The SWR was way high, like 4:1.  I think this was due to the close
proximity of electrical wires.  The antenna would probably have worked fine
with a tuner.
Rick Dettinger
K7MW