My original post (way back) was about how I used my Nano VNA to help make my 140 ft closed loop tune up better on 40m.
It was a simple post about the instrument, the Nano VNA.
I did not intend that post to then become a series of responses about antenna design.
Someone asked about my ¡°vertical¡± on 40m and 80m.
It was a military surplus alum tubing (very light) that was tapered.
It came in two ft sections that closely fit.
So I put up about 35 ft of alum tubing and just lashed it to a taller fir tree.
I then ran two horizontal counterpoise wires, about 35 ft each, about 10 feet above ground.
So I only had two ¡°radials¡±.
It was (is) so simple, but it is not ground mounted. Then I¡¯d have to deal with multiple radials on the ground.
When I listen at night to DX stations, this vertical beats my dipole and loop by a few S units.
But it is pretty awful for a short skip (300 mile) daytime contact.
So it shows a simple low-angle propagation path, good for DX, but lousy for NVIS.
Now, getting back tothe Nano VNA.
How did I use the NANO VNA to tune my 140 ft loop? Look at the graphs.
I used it to first check the resonant (zero reactance) frequencies.
I used it to look at the PHASE graph.
I used it to double check the Smith Chart.
The SWR was as predicted, lowest at the low end of the 40 m band.
I really did not ¡°need¡± the NANO VNA instrument to make my horizontal 140 ft loop work!
but it was reassuring that the graphs did not show me something unexpected.
de k3eui barry
Barry K3EUI