Over on his channel Tech Minds has uploaded a new video where he tests the N1201SA / PS100 vector impedance analyzer. This is a US$160 antenna analyzer from China that allows you to measure the VSWR of your antennas. In the video Tech Minds explains a bit about VSWR, and goes on to show the unit in action on several of his antennas.
Compared to the NanoVNA V2 these units seems less useful with a smaller frequency range, and are also more expensive. The unit is also only 1-port, meaning that it can only do S11 measurements and cannot analyze devices like filters. But on the other hand it does come in a metal case with a battery and has a fairly easy to understand and use interface.
Easily Check Your Antennas Tuning - VNA N1201SA / PS100
A Vector Network Analyzer (VNA) is an extremely useful tool for radio hobbyists as it allows you to measure and tune antennas and filters, as well as measure cable loss among other applications. Until recently low cost VNA's cost hundreds of dollars. Then came along the original NanoVNA which brought expensive VNA capabilities to the masses with its low $40 pricing. But the original design is limited to a maximum frequency of only 900 MHz. The new V2 design pushes this maximum frequency up to 3 GHz officially, and unofficially up to 4.4 GHz with reduced performance. It also improves on overall dynamic range and maintains the affordable sub $100 price. We note that the NanoVNA V2 is unrelated to the original NanoVNA apart from being the inspiration, and sharing the same firmware base.
Over on YouTube Robert J. Meade has been uploading a series of videos demonstrating and teaching viewers how to use the NanoVNA V2 to measure various devices. For example in his videos he shows how to use the NanoVNA V2 to measure one of our RTL-SDR Blog Broadcast FM filters, how to measure a log spiral & clover antenna, use measurements to rebuild a variable attenuator, measure an active device (SAWbird+ NOAA), and how to measure a DIY microstrip L-band LNA. If you're just getting started with the NanoVNA V2, then these are some great videos to start with.
NanoVNA V2 First Measurements V2: Log Spiral & Clover Antennas (Above 900 MHz & up to 3GHz)
We've received a few notices that the NanoVNA V2 design that we've been following since last year is now available for sale on eBay and Tindie (or Taobao if you live in China). The original official sales appear to have been from Tindie, where it is priced at $58.25 + shipping, although it is now out of stock. On eBay resellers are selling it for up to $150. If you're interested in purchasing the V2 we recommend entering your email into the Tindie form as they will notify you when it's back in stock. Initial reviews posted on the Tindie store indicate that the unit has excellent performance for the price so we expect that it will be popular enough to manufacture many more in the future.
The original NanoVNA brought expensive Vector Network Analyzer (VNA) capabilities to the masses with it's low $40 pricing. A VNA is an extremely useful tool for radio hobbyists as it allows you to tune antennas, filters and measure cable loss among other applications. However, the original design was limited to only a frequency of 900 MHz maximum. The new design pushes this up to 3 GHz official, and unofficially up to 4.4 GHz whilst also improving dynamic range and maintaining the low price point.
The description and specs of the NanoVNA V2 are shown below:
3GHz second generation NanoVNA vector network analyzer, designed in collaboration with OwOComm.
Note: Micro USB cable not included. Fully assembled, without enclosure. Ships within 5 business days.
However, SWR is only partial information and tells us nothing about the actual gain and directivity / radiation pattern of the antenna. The radiation pattern tells us in which direction the antenna receives and radiates power best from. For a Yagi, we would expect the best reception gain to come from the front, with much less gain on the sides and rear.
To set up the radiation pattern measurement, Jephthai connected the Yagi to the TX port of the NanoVNA via a long coax cable, and connected an omnidirectional whip antenna to the RX port of the NanoVNA. The NanoVNA and Yagi are separated by a reasonable distance of 18' to ensure that the far-field radiation pattern is measured instead of the near-field pattern. He then measures and collects the S21 reading over multiple rotations of the Yagi.
The data is then plotted revealing a two dimensional radiation pattern for the Yagi. As expected gain is highest in the front, and weaker on the sides and rear. Jephthai notes that the radiation pattern mostly matches what the MMANA antenna modelling software predicted too.
With the NanoVNA (and upcoming NanoVNA 2.0) being so affordable and readily available many budget focused RF enthusiasts and hams are now adding a tool to their arsenal that used to only be for the wealthy and commercial users. Vector Network Analyzers (VNAs) allow you to do things like make SWR measurements on antennas, characterize RF filters and detect coax cable faults, among other applications.
However, much like the RTL-SDR there is no one company or entity controlling the NanoVNA concept or development. The NanoVNA name now encompasses a mishmash of similar but slightly different hardware created by multiple manufacturers/community members, and multiple firmware and software developed by the community. This can be frustrating for some people as community developed products typically do not have full manuals and support that you would find in products from a larger commercial company. Instead some time to research and understand the product may be required.
Whilst almost plug and play, to use the NanoVNA you still need to understand what a VNA is, how to calibrate it, and how to read it's measurements. And in addition, for the NanoVNA in particular you'll want to know the differences in NanoVNA versions, how to update the firmware and where to find optional PC programs for it.
In order to help people new to VNAs and the NanoVNA, Christoph Schwarzler (OE1CGS) and Maximilian Schwarzler (OE1SML) have written a Kindle eBook called "A guide to the NanoVNA". The guide goes over what a VNA is and how it works, NanoVNA hardware versions and what to avoid, what accessories you might need, how to update the firmware, how to read the various charts, how to navigate the menus, how to calibrate and how to use NanoVNA PC software. The book also goes over some use cases for the NanoVNA, including creating a loading coil for a 40m short vertical antenna, creating a band pass filter, and checking for coax short circuit defects. At only US$2.99 it's a good way to get started with the NanoVNA.
Thank you to RJ Juneau (ylabrj / VA3YLB) for sharing with us his NanoVNA firmware update guide for idiots. NanoVNA firmware is updated fairly often, so this is a good reference guide for those who want to test the latest code as updating the firmware is a multi-step process. He writes
I've put together a "for idiots" document (I'm both the writer and the target audience) that holds your hand through the process of upgrading from Windows, and covers some important issues like:
Are you using a nanoVNA or an updated nanoVNA-H?
Where to pick up the right software for the board
Do you want the VNA or the antenna analyzer version?
Back in October 2019 we posted about the upcoming NanoVNA version 2.0 which back then was still being designed with a predicted release date of January 2020. Recently some photos of the NanoVNA 2.0 prototype have been uploaded to the NanoVNA groups.io forum.
The NanoVNA 2.0 is expected to retail at around US$60 which is around the same price as the current NanoVNA. The current NanoVNA is limited in that it can only measure from 50 kHz to 900 MHz, with performance being reduced above 300 MHz. It can be extended to 1.5 GHz, but with severely reduced performance. The NanoVNA 2.0 will be able to measure from 50 kHz to 3 GHz, and possibly up to 3.5 GHz. Version 2.0 will also have improved dynamic range.
The NanoVNA (v1.0) is a versatile Vector Network Analyzer (VNA) that was originally designed by @edy555 / ttrftech. What makes it so special is it's extremely low cost as it can be found on eBay & Aliexpress for under US$40 and on Amazon for around US$50-US$70. A VNA is an extremely useful tool in any ham or RF enthusiasts tool belt as it can be used to measure RF filters, tune antennas, measure coax cable loss, and find cable faults.
NanoVNA Version, Model, Naming and Credit Confusion
Eddy555's original NanoVNA design has already been released for several years prior to the current NanoVNA popularity boom, but during those years eddy555 was only selling the product in small quantities as a DIY kitset.
The current low cost NanoVNA's available on the market now are mostly the "hugen" version known as the NanoVNA-H. Hugen is a ham who innovated on eddy555's original open source design, adding features like battery management, improved PCB layout, PC software and extending the frequency range from 300 MHz to 900 MHz.
There is now also the "NanoVNA-F" version available which is a clone of the "NanoVNA-H" but with a larger 4.3" screen, larger battery, range extended to 1 GHz, and firmware based on a RToS. It sells at a much higher price of US$110 - US$129.
Finally, we note that the NanoVNA 2.0 project described in the first part of this post does not appear to be affiliated with eddy555 or hugen in any way. Development of the NanoVNA 2.0 is apparently based on completely original design work, and only shares similarity to the original NanoVNA in terms of pricing, name, and firmware compatibility. NanoVNA 2.0 is being developed by OwOComm which is a Japanese research unit that aims to promote "intellectual communism".
OwOComm note that they will release the designs as open source without actually manufacturing the product. It's then up to any factory to manufacture and sell the design as they please. OwOComm themselves appear to be sponsored by an unnamed customer of theirs who wanted an "improved NanoVNA" to be designed. It's not clear what the goals of OwOComm or their unnamed sponsor is, other than perhaps philanthropic.
At the same time we note that eddy555 appears to be designing his own NanoVNA 2.0 version which is not affiliated with the NanoVNA 2.0 described in this post. In the forum thread eddy555 has urged OwOComm to rename their project to avoid confusion, but it is unclear if they will do so.
The story of an open source project running away from the original developer seems to be a fairly common one these days. While eddy555's original open source design has started something truly great, it is at the same time sad that he won't see much credit or profit from future designs.
Previously we've been posting about the NanoVNA which is an open source VNA project by @edy555 / ttrftech that has recently become extremely affordable at less than US$50 for a fully assembled unit thanks to Chinese manufacturing (or a little more if you order it via Amazon).
Over on the NanoVNA groups.io forums we've seen discussion about a NanoVNA hardware version 2.0 being in the works and it could be ready as soon as January 2020.
The nanoVNA [v2] will eventually reach 3GHz (and at a similar price to version 1).
It's going to be based on the adf4350 + si5351.
The 3 mixers are replaced with one higher spec mixer (ad8342) that is switched between the 3 channels.
A variable gain amplifier is added at baseband using one opamp and switched feedback resistors for improved dynamic range.
The Audio codec is removed and the stm32 built in ADC is used instead.
The performance should be comparable or better to V1.
Info about the baseband VGA design: A RFIC switch is used to switch the shunt resistor in the feedback path. The switch is basically "transparent" because the off state capacitance is in the femtofarad range (it is an RF switch) which is negligible at the IF frequency. The on state resistance is small compared to the resistors being switched in. Since the amplifier gain is mainly dictated by the feedback network, and the switch is "transparent", there is nothing other than the tempco of the physical resistors that can cause a temperature dependence. The RFIC used is the same as for the receiver RF switch, and it turns out all the maxscend switches do not have the shunt diode problem (most RF switch ICs have parasitic diodes from RF input to ground which will start to conduct at lower frequencies), so it has no theoretical lower frequency limit and can be applied at the IF frequency. This is a big improvement over using normal analog switch ICs which have capacitance in the pF range.
Info about linearity: The code will perform a calibration of each VGA step on boot up. Since there is no temperature dependence the calibration only needs to happen once.
The layout designer has also posted, noting that the price will remain the same (roughly $50), but there will be several improvements including a wider frequency range, better dynamic range, and an improved PC interface.
Hi, NanoVNA V2 layout designer here. Here is what I know:
V2 won't have a bigger display because it is too expensive
frequency range will go to at least 3.5GHz; PLL limit is 4.4GHz.
ADF4350 is used because of cost reasons; ADF4351 is more expensive by a factor of 5.
The layout is already fairly packed, so modular is not possible without a huge form factor.
Layout and shielding are much improved for higher dynamic range.
Price will be around the same as the existing NanoVNA. The design is already cost limited, so we can not do anything that will further add cost.
PC interface will be completely reworked. A binary protocol will be used similar to the xaVNA (we are going for full compatibility with the xaVNA PC software). If you are writing custom PC software for the Nano, please make sure the USB interfacing part is well abstracted away and easy to change.
The development timeline is going to be pretty long (by Chinese standards at least). We will iterate on PCB layout to get the best dynamic range. I think we might see initial (quantity limited) sales in ~3 months.
Just as a footnote, we received several emails from readers who wanted to make sure we note the credit edy555 should get. Originally edy555 had planned to produce his own units, but due to a Chinese ham enthusiast who had good intentions the design became popular and was soon cloned. We note that the NanoVNA v2.0 does not appear to be affiliated with edy555.