You need to see what X shows.
When X=0 that is the resonance point. It is how you know if it is long or
short, or just in place.
After that, while X=0 (or around), it is when you check R. That is the real
impedance, it is the one you will need to transform to 50 OHm.
Both together, R and X will calculate final Z.
The theory says a 1/4 vertical in perfect condition will be around 36 Ohm (R=36
OHm, X=0), but that perfect point is difficult to reach.
You can export the Touchstone file from your RigExpert and import it to ZPlots
Xtra and get extra plots;
Zplots_Xtra.xlsm<http://www.puertobalsillas.com/radio/Balun_Guanella_4_1/Zplots_Xtra.xlsm>
73, Maximo - EA1DDO
________________________________
On 12/2/2018 12:07 PM, Jamie WW3S wrote:
> trying to understand a 40m vertical, my Rigexpert analyzer has Z, X, R and
> C.......when I measure the vertical at 7.125 (target freq) the SWR is 1.3:1,
> but the Z is 50 ohms, I’m told the impedance needs to be 39+j) ohms? How can
> I read that with my rigexpert.....I can get around 39 ohms at 7.400.....is my
> vertical too long, or too short?
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