I thought this was a fair question, so I tried it. I laid out about 8 ft of
stranded wire about 16-18 AWG. Poked a few strands into a female SMA
coupling. Connected that to about 4' of RG-316, which was attached to my
nanoVNA. I did a scan of 50Mhz to 500Mhz. I could see multiple SWR dips on
the screen. The first was at 56.75 Mhz, so I guess it works.
On Mon, Jun 20, 2022, 21:05 Roger Need via groups.io <sailtamarack=
[email protected]> wrote:
On Mon, Jun 20, 2022 at 05:38 PM, Brian Donaldson wrote:
I'm not building an antenna. All I want to know is if the NanoVNA can
show me
return loss peaks with a single length of stranded wire. Nothing more. I
have
an antenna and it works just fine. Don't need an antenna.
If the NanoVNA cannot do a single wire return loss reading, then fine.
Measuring Return Loss means you are sending power to something and
measuring the power returning back to the source. Then the calculation can
be made.
You can't calculate RL to a single wire just suspended in the air. You
either need a ground reference or another wire in order to get current
flow. In both of these cases an antenna is being constructed, it will
radiate and it will have resonant frequencies. You can measure the RL at
the connection point to the wire and the other side (ground or wire).
Changing the length of the wire, the ground conditions or other wire
characteristics will result in different RL measurements.
If the wire suspended in the air has another one running parallel then you
have a transmission line instead of an antenna. Connecting a load on one
end and you can measure RL at the other.
Roger
