This is a work in progress page about the NanoVNA (Vector Network Analyzer) project that produces these magic boxes for about $50. Make sure that you get a device that has open, short, and load calibration connectors. Then get some connectors to connect this SMA device to the F, BNC, PL-259, and N connectors that you probably are using around your shack.
How To Get Started With Your First VNA
If you have one of these magic devices in your hands, you will want to start by checking the SWR of an antenna. The IMSAI Guy has a great video that will take you from zero to testing your antenna in under 19 minutes. Watch this one and you will be testing your antenna in ‘no time.’
Videos Training Series
Once you have mastered checking out the SWR of an antenna, Alan Wolke W2AEW has a great set of videos that will get you doing more with your NanoVNA. These videos will drag you through all of the prerequisites so you can start using this magic device for lots of cable/antenna tests.
Watch these at your own risk; they can become rather addicting. Yes, it’s OK to hit the pause or watch them more than once if you start hitting topics that you’re not familiar with.
Step 1 –> What is a Vector Network Analyzer (VNA) #312?
This video presents the basic definition of a vector network analyzer (VNA), a practical view of how some of the measurements are performed, and an introduction to some of the common measurements that are made. A few examples VNAs are shown. Knowledge of transmission lines, reflections, VSWR, etc. is helpful, but not required for this video. (See those below.)
Step 2 –> Learn About Directional Couplers
The VNA makes comparisons of waves traveling in both directions on one or more cables. Wave information is generated using directional couplers to differentiate the signals traveling in or out of a circuit. Knowing how these couplers work is the purpose of this step.
Step 3 –> Learn about Transmission Lines, Reflections, and Standing Waves
Step –> Learn about the Smith Chart
You knew it was coming. Complex Math, circle charts, and more dB than you ever thought was possible.
Step –> More to Come…
Groups
The definitive source of information is located on a Groups.IO page. Anyone can join, at this link.
Version 1
The “version 1” of these devices is available on eBay or Amazon.
Version 2
There is a second-generation model in the works. The RTL-SDR folks have a great discussion of the changes between the first and second-generation boxes. The newer boxes are currently running about $100, and are available on AliExpress at this link.
Links
- https://www.eevblog.com/forum/rf-microwave/nanovna-custom-software/
- https://oristopo.github.io/nVhelp/html/Menu.htm
- https://drive.google.com/drive/folders/1IZEtx2YdqchaTO8Aa9QbhQ8g_Pr5iNhr
- https://github.com/erikkaashoek/Tapr-VNA
- https://groups.io/g/nanovna-users
- https://www.thingiverse.com/search?q=nanovna&dwh=975de9a1a9c61f7
When Calibrating the NanoVNA is Needed
NanoVNA’s need to be recalibrated and none of those involve factory calibration techniques. Using the device in a different way requires extra effort.
- When you use a different test setup, or where the “reference plane” for the measurements is moved. For example, if you change the lengths of the test port cables, and your calibration has been done at the end of the cables.
- If you use a different measurement frequency span than the frequency span of the current calibration. If you calibrated from 0-100 MHz and now you’re testing a device from 200-300 MHz, the measurement might not be valid. Or, calibrated from 0-800 MHz, and then measured from 20-30 MHz.
- You can’t remember what your calibration setup is.