[TowerTalk] New Tower/Antenna Installation

[Tom Rauch]

> What most of them are doing is responding to figures like these for a 3
> element 40 over good flat terrain:
> 
> 100   5.7   10.7   12.7   13.0 @ 18.5 d
> 090   4.8   10.0   12.2   12.9 @ 20.0 d
> 080   3.9   09.2   11.6   12.7 @ 22.5 d
> 070   2.8   08.2   10.7   12.4 @ 25.5 d
> 
> The particulars for a given height and gain might change with antenna, but
> the SHAPE of these figures will remain the same. It IS true that there is
> a nasty high angle lobe at 100 feet, which can let in a lot of stateside
> QRM, maybe 15 dB difference between 70 (least) and 100 feet (most local
> reception). But the gain at five degrees above the horizon changes almost
> a dB per 10 feet !!

Well put Guy!

I watched a ZL2, on bad advice from others, give up almost 3 dB at 
a desired angle because he lowered his antenna height to 
suppress what everyone told him was "wasted energy".

My 40 meter is at 130 feet, I'd have it at 160 feet if I could.
73, Tom W8JI
w8ji@contesting.com

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