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Old May 13th 07, 11:41 PM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Dec 2006
Posts: 1,169
Default Tuning an antenna

Buck wrote in
:

Currently, I am tuning my gutters up for HF. I checked it with an
analyzer the other day and found it is an excellent 160 meter and 20
meter antenna without the tuner (swr-wise). In the meantime I am
building a vertical for 20 and up.


I don't know if there is a different meaning for the term gutters on your
side of the big pond, but if you mean the parts of a building for
collecting the rainwater from the roof...

Roy has talked to you briefly of the near field / induction fields. The
closer you place your antenna to noise sources (eg appliances, including
switched mode power supplies), the greater the response of your antenna
to those sources.

You have probably heard of the square law of light that tells you that
the power density of an EM wave decreases with the square of distance.
That is true in the radiation far field, but in the near field, the
induction fields decay more rapidly that that, and every bit of distance
you can put between your antenna and noise sources is worthwhile.

Wrapping your noise sources with your antenna sounds a sure fire way to
couple the very most interference... is that what you really want to do.

Owen