[Elecraft] ATU problem or Law of physics problem... I don't know which

[cptpatmcd]

So, if I understand you right...  Sorry about getting OT here.

I can make it resonant by extending it about 1 foot on each end?

33 feet/x=7.09/7.3

x=~34

My main problem are junipers.  I can raise the antenna about 20' in the air
but then the antenna is literally in the trees.  Would that create more
problems that it solve?



Ron D'Eau Claire wrote:
> 
> Such a low dipole will normally have, at its center, an impedance in the
> general range of 4-j60 ohms at 7 MHz, so the "r" value you're seeing
> doesn't
> seem surprising.
> 
> For all practical purposes it's "on" the ground and the earth has a very
> large effect on its impedance and its resonant frequency. In that case
> it's
> closest to resonance at about 7.3 MHz where the impedance will be close to
> 4.7+j0 ohms. The SWR bandwidth is very broad because of the huge resistive
> losses of the earth. Even so, it should show pretty good performance as an
> NVIS radiator for local contacts.
> 
> You didn't mention the type or length of feed line. Since it has a high
> SWR,
> it will have a huge effect on the impedance the KX1 sees. For example, if
> it's 50 ohm coax the SWR will be something like 33:1.
> 
> By comparison, the same antenna at 30 feet up will be self resonant at
> about
> 7.1 MHz where it will show an impedance of 70+j0 ohms, giving you an SWR
> of
> less than 1.5:1 when fed with 50 ohm coax. 
> 
> Ron AC7AC 
> 
> -----Original Message-----
> 
> Hmm....
> 
> I have a 66' (20m-ish) center fed dipole at 6 feet off the ground in my
> back
> yard.  The ATU in my KX1 reads P 0.3 and r9.9 at 7090 khz.  This doesn't
> look right to me.  Did I dork something up when I twiddled the knob?
> -- 
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