NanoVNA SWR reading made simple

[Elf36]

So, I bought a NanoVNA over a year ago and was a bit intimidated by it. So much stuff on the screen. Multiple traces and Smith charts etc. All I ever wanted was to use it as a cheap antenna analyzer to read SWR of whatever range, inside or in the field. I started looking for videos on how to use it again today and found exactly what I was looking for. A straightforward instruction for SWR. I re-watched the video when I got home and have already swept 2 antennas. It's like I got a brand new item to use. It shows you how to eliminate all the crazy lines etc, which makes it confusing (For me anyway) and just shows it with one line on the screen.  I'm really excited to make use of it and build more antennas. If you are looking for the same, see the copy/paste link below.

https://www.youtube.com/watch?v=QJYeFpiqY8c 

If you have any issues- The video is called 'NanoVNA Made Simple' #480 (Run time is 18 mins 39 seconds)

[RobRich]

Good stuff for those not familiar with the NanoVNA user interface. :) I have read about professional VNA users even being puzzled initially by some of the NanoVNA menus and options. UI quirks aside, it is quite the neat device for the price.

Taking the next step beyond SWR, I like to use my NanoVNA-H4 to check complex impedance in addition to SWR.

Even just simple resistance (R) will tell ya' more about the SWR reading. Say one has a typical 50-ohm transceiver. The measured antenna SWR is 4:1. Is the resistance closer to 200 ohms or 12.5 ohms? ;) Kind of makes for a considerable difference if using to a matching transformer for example by at least telling ya' which way to position the ratio.

Reactance (X) is also nice to have IMO. An antenna often is "resonant" at the frequency where X is zero, which can make a routine task like lengthening or shortening an antenna's length a little easier to determine.

Also, yeah, I agree about Smith Charts. I might learn to use them if building complex circuits, but admittedly, I have never bothered seriously with them even despite having a degree in math. I am not sure if seeing Smith Charts makes me think about my old HP-49g graphic calc.... or a slide rule.

[Radio Krasnoprudskoe]

Simple!
Touch the screen and go to Stimulus -> CW FREQ and set that to the desired frequency. the yellow line is your swr.
NANO VNA is a saviour when it comes to MW and lowfer antennas!

[Charlie_Dont_Surf]

I have read about professional VNA users even being puzzled initially by some of the NanoVNA menus and options.

I use top-end VNAs that cost several hundreds of thousands of dollars on daily or weekly basis and I was comfortable with my NanoVNA quickly, though I must admit that the "transform" submenu was somewhat alien to me.

Even just simple resistance (R) will tell ya' more about the SWR reading. Say one has a typical 50-ohm transceiver. The measured antenna SWR is 4:1. Is the resistance closer to 200 ohms or 12.5 ohms? Kind of makes for a considerable difference if using to a matching transformer for example by at least telling ya' which way to position the ratio.

Reactance (X) is also nice to have IMO. An antenna often is "resonant" at the frequency where X is zero, which can make a routine task like lengthening or shortening an antenna's length a little easier to determine.

Also, yeah, I agree about Smith Charts. I might learn to use them if building complex circuits, but admittedly, I have never bothered seriously with them even despite having a degree in math. I am not sure if seeing Smith Charts makes me think about my old HP-49g graphic calc.... or a slide rule.

In many decades of working in the RF and electronics industries, I can say that, while we sometimes talk qualitatively and non-quantitatively about "standing waves", I can't recall ever being asked for or seen a VSWR value quoted on any of the data I produce or read - we're more concerned about return loss, S11/S22 and the specific impedance presented as R+jX along with where that is on the Smith Chart.

Having said that, you can probably have even the most expensive VNAs produce a VSWR trace, especially older ones; it's available on the menus. On the newer VNAs, you might have to dig into the math functions to have it calculate it for you, because it might not be something readily available on the list of possible traces to display. I'm not 100% sure about that though because I never need to enable a VSWR trace because none of us care about it. (See above.) My point is that while that measurement is available, nobody in my "realm" is using it, in lieu of more specific measurements, for exactly the type of reasons you list above.

You probably don't need to worry too much about Smith Charts as a hobbyist if you are not building circuits that have to produce a specific match on the inputs and/or outputs.

[RobRich]

Specs and features aside, the nice usability aspects about Agilent, Keysight, or similar desktop VNAs are having actual keypads and visually mapped menus.

I agree about VSWR. I am more concerned about reactance than VWSR, then I can work with the system impedance as necessary to derive a complex conjugate match. The thing is most first-time NanoVNA users are going to initially treat it as a basic antenna analyzer, which is a good place to start for learning purposes.