[TowerTalk] precipitation static & folded verticals
Mon, 22 Jan 2001 15:39:45 EST
In a message dated 1/22/2001 2:03:21 PM Eastern Standard Time,
> But, before I do, can you (Yuri) explain to me why the electrically
> longer (folded and top loaded) structure was inherently quieter than
> the naturally resonant monopole structure when they are both
> resonant at the same frequency? I sure don't know the mechanics
> here. Can you give me some basis for the results of the test or
> where I went wrong?
By using series capacitor you are basically matching (longer) radiator to
your feedline, but the longer radiator has different radiation pattern - more
compressed to horizon and narrower lobe(s) - different from quarter wave
radiator. Both antennas are "looking" at different environments and having
different gain figures.
The pattern is dependent on the antenna's length (properties) not the match.
Quarter wave, vs. half wve, vs. 3/4 or 5/8 wave (and longer) have different
radiation patterns, regardless of matching situation and "see" different
signals/noise depending on local situation.
If you have EZNEC, you could model both antennas and compare the radiation
patterns and see the difference.
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