Because it is resonant at too low an R value.
R=30, X=0, SWR = 1.67
The impedance curve is exactly where I want it except for it being a bit low, so the 2:1 bandwidth points are shifted away from where I need them. If R was 50, it would be perfect! So I would like to add 20 Ohms...
It was the classic design in the ARRL Antenna book for a 2m 5/8 wave, Which I would actually model as:
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|-(G)-////-(+)-///----------<|
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Doc, is that not one loading coil (which I call series inductance) with one more coil to ground (shunt inductor)?
After fiddling with it for a while and determining, while I could get it to load nicely with good match, that my build exhibited about 3 dBd loss, I went with a simpler design:
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(G) (+)-///----------<|
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The simpler design also loads up nicely with fairly good match, and exhibits about +3 dBd.
But the question is more generic, how to add more R without affecting X?
