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Re: Starting trouble for NanoVNA!
I will try that next time!
73 Jon, VU2JO On Mon, Feb 17, 2025 at 10:54?PM Barry Leonard KN4JRF via groups.io <w9jbl= [email protected]> wrote: I have the same problem. Nanovna-H, Firmware V. 1.2.40. Had it for |
Re: Adapting the LiteVNA for SAR?
? Use S21 mode with an amplifier.
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People have been using VNAs as radars for years. The NanoVNA just makes it easier. Dealing with the big first reflection is tricky. One way is to use a separate cancellation path that is adjusted to null the first reflection. ?That’s what we did for the FINDER victim detection radar. FINDER: Radar for Locating Disaster Victims ( ) jpl.nasa.gov ( ) ( )
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Re: testing non-50 ohm filters was Re: [nanovna-users] NanoVNA port renormalization
Thanks, Don. Your filter shows much more response variation with a capacitive load than the 230 kHz filter in the Murata curves. I don't think anyone adds capacitance on purpose. In the past I have used pots instead of fixed 330 ohm resistors and adjusted them for minimum detected audio distortion. Since I now have quite a few spare filters, these days I just swap in another one, trying both orientations for minimum distortion.
Before I wrote this program, I used to worry a lot more about audio distortion: Brian |
Re: testing non-50 ohm filters was Re: [nanovna-users] NanoVNA port renormalization
Hi Brian,
I went ahead and tested the filter response using a 10 pF, 33 pF, and 68 pF load capacitor. Attached are 3 plots and the reference plot on each of the attached plots is when I'm not using a load capacitor. It should be noted that the curves shown in the datasheets you attached have the left vertical axis identified as attenuation in dB. In reality it appears that axis has been normalized based on the peak of the response curve. In my attached plots I have not normalized the vertical axis so you can see what the true attenuation is through the filter. Just FYI, Don |
Re: NanoVNA-H Connecting
OS is Win 11 Pro
I've changed USB-A/usb-c cables that was the first issue. I connected my phone to this cable and saw data, I believe the cable I'm using can communicate with the NanoVNA. I'm not seeing the Port COM device connection from the NanoVNA. I went through the STM32 Bootloader installation and the STM Device in DFU Mode is showing up under the USBC grayed out. Attempting to connect out of DFU Mode, returns an unknown USB Device message. So in either mode can not connect to the NanoVNA. Attempted to change the configuration connection, both Serial (Serial speed 3800) and USB. Thank you for your feedback, Stan and Bernie! |
Re: Adapting the LiteVNA for SAR?
Thanks, Kent.
I'm more interested in using signals through air. The front-end of the LiteVNA was described here: /g/liteVNA/topic/99749985#msg1054 I see I made a mistake in my 1st post. The liteVNA doesn't use a similar DSP to the nanoVNA but uses the uP's internal DSP and several switches. However, all the switches can be statically set: reflect=open, Rx/tx synth set to ADF4350, rcv & ecal connected to ports. Then control Tx & Rx from external controller. |
Re: Starting trouble for NanoVNA!
I have the same problem. Nanovna-H, Firmware V. 1.2.40. Had it for several years.
Also the menu seems to start by itself, and go into whatever setting it feels like. Maybe case is interfering with the touch screen. sometimes I can press lightly on case and the menu acts randomly. |
Re: Adapting the LiteVNA for SAR?
Hi Larry
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I have worked on several GPR projects.? One is currently looking for land mines in SE Asia. A LOT of loss going though dirt.??? And a big impedance bump at the air/dirt interface.? They really need much more power than the Nano puts out.?? And since the same port is Tx and Rec, an amp will not be simple.????? But lots of neat stuff down there.?? Kent On Monday, February 17, 2025 at 10:17:28 AM CST, Larry Rothman via groups.io <nlroth@...> wrote:
Folks, Using the NanoVNA as a signal source for Ground Penetrating Radar (GPR) was discussed a couple of years ago. Today on Hacker News, there is an article about a home-built Synthetic Aperture Radar (SAR) unit using a freq around 6GHz. The article discusses theory and the problem of finding a suitable Rcv A/D. The LiteVNA has the freq range, is capable of resolving nS time (to a certain amount), can measure phase and is programmable. The big issue is probably the switching time of the generator/reflection ICs in the front-end of the LiteVNA. As for the A/D spec, would the heterodyne method and DSP used be a limiting factor? So - might it be feasible to make use of the LiteVNA in a simplified radar setup using an external controller and appropriate antennas? Could the TDR routines be adapted? Could the LiteVNA be used with a TinSA-Ultra and a controller for something? Just thinking out of the box here. In my 60+ years of Tech, I have always looked at repurposing stuff. So, instead of "not possible" answers, I would rather hear what might need to be changed (electronics /software) to achieve a minimal proof of concept. Thinking caps on.... ... Larry |
Adapting the LiteVNA for SAR?
Folks,
Using the NanoVNA as a signal source for Ground Penetrating Radar (GPR) was discussed a couple of years ago. Today on Hacker News, there is an article about a home-built Synthetic Aperture Radar (SAR) unit using a freq around 6GHz. The article discusses theory and the problem of finding a suitable Rcv A/D. The LiteVNA has the freq range, is capable of resolving nS time (to a certain amount), can measure phase and is programmable. The big issue is probably the switching time of the generator/reflection ICs in the front-end of the LiteVNA. As for the A/D spec, would the heterodyne method and DSP used be a limiting factor? So - might it be feasible to make use of the LiteVNA in a simplified radar setup using an external controller and appropriate antennas? Could the TDR routines be adapted? Could the LiteVNA be used with a TinSA-Ultra and a controller for something? Just thinking out of the box here. In my 60+ years of Tech, I have always looked at repurposing stuff. So, instead of "not possible" answers, I would rather hear what might need to be changed (electronics /software) to achieve a minimal proof of concept. Thinking caps on.... ... Larry |
Re: NanoVNA-H Connecting
Roger, we will need a little more info to help you effectively.
Which OS and version are you using on your PC? Win10/11? Win7? Win8? some flavor of Linux? But a couple of first notes: 1. Don't use an OTG cable (those are for the USB micro-B connectors). A normal USB-A to C data (not charging) cable is required. For USB-C, OTG is normally a software function, but if your cable somehow does force OTG, it is the wrong mode for nanoVNA. 2. Assuming you are using some version of Windows, open Device Manager. Then expand the line that says "Ports (COM & LPT)" so you can see the individual devices. Plug in the USB cable and turn on your nanoVNA. You should see a new COM device appear. Note its identifier (e.g. COM6, COM10). When you turn on/off the nanoVNA, this device should appear then disappear. When you see this happening, you know that your cable and nanoVNA are correctly communicating with the computer. Only after that should you try to connect with a software program, and you need to select in that software program the identifier of this COM port and tell it to connect. I hope that is helpful. Stan KC7XE |
Re: NanoVNA-H Connecting
On a PC, go into Device Manager and verify if the PC is detecting the NanoVNA port when the connected NanoVNA is powered on.
You should see something like “USB Serial Device (COMx)” where x will be the COM port number. If you do not see a the above message, try another USB port and also another USB cable. -- Bernie Murphy, VE3FWF *Real* radios glow in the dark |
Starting trouble for NanoVNA!
I am a new NanoVNA user. Mine is an H v3.6. No firmware updates have been
done. I have been using it only for a few days. Sometimes, on sliding the switch on, the screen is blank, but the blue LED is lit. After a few on/off cycles, the screen becomes functional and I can use it. Does any of you have a similar problem? Jon, VU2JO |
Re: NanoVNA App - Installation and Use
#applications
Many thanks ddemos1963 for sharing your success in making NanoVNA App works with Wine in Linux.
I also use only Linux. In Wine I ran NanoVNA-App-Setup-V1.1.209-0D18.exe and the installation went flawlessly. With your explanations (32 bits, windows 10, registry edition) I now have NanoVNA App fully working. In my case I did not have to install gdiplus. Here is my configuration : Archlinux up to date Wine 10.1 NanoVNA-H : hardware 3.4, firmware 1.2.40 ; mapped to /dev/ttyACM0 This is a great application easy to use. Congratulations to the developers. Pascal |
Re: testing non-50 ohm filters was Re: [nanovna-users] NanoVNA port renormalization
Nizar,
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With only S11 and S21 measured, the renormalization depends on the symmetry of the device measured. Most passive linear devices have S21=S12. (Isolators are an exception.) Many filters have S11 about equal to S22, and the renormalization will succeed based on just how close to equal they are. Filters with significantly different input and output impedances will not be properly renormalized without measurement of all 4 S-parameters. Some ceramic filters do show noticeable S11/S22 differences when reversed, while others look pretty close. I wouldn't depend on renormalization on the NanoVNA for something like device acceptance where good accuracy is needed. --John On Sat, Feb 15, 2025 at 11:44 PM, Team-SIM SIM-Mode wrote:
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