One data point - when W3YOZ ran some (informal) tests a few years ago,
comparing performance of his vertical in the trees with the one in the open,
he determined that performance was degraded significantly during the months
that the trees sap was up (spring through autumn). We theorized at the time
that trees are like giant columns of water and do absorb MF rf to the tune
of several db. In the winter when more of the moisture is in the roots, the
effect is less.
No, it wasn't a scientific test in the pure sense of the term, but the other
antenna did provide something of a control and the results were impressively
consistent from one summer to the next. The trees were very close to the
vertical, very large (dense), and approaching 100 feet tall.
(I have observed that my beverage systems (running entirely through hardwood
forest) seem to be a bit more efficient in the winter too. Just anecdotal
info though.)
John, K4IQ
----- Original Message -----
From: "Ford Peterson" <ford@cmgate.com>
To: <topband@contesting.com>
Sent: Sunday, October 12, 2003 10:23 PM
Subject: Re: Topband: Vertical in the woods
> Not exactly scientific, but the empirical evidence speaks volumes. Check
> out this guy's "tree antenna."
>
> http://www.qsl.net/kf4bwg/treeant.htm
>
> It seems to me that if the trees are a significant fraction of 1/4 wL on
> topband, they will absorb power. Whether they 're-radiate' that power,
> well, who knows.
>
> Ford-N0FP
> ford@cmgate.com
>
>
> _______________________________________________
> Topband mailing list
> Topband@contesting.com
> http://lists.contesting.com/mailman/listinfo/topband
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