Date   

Re: Smith Charts showing Reflection Coefficient and SWR

Barry K3EUI
 

Oops I messed up the 0.9 reflection coefficient with SWR close to 20
It looked too small when I made this.... but I can blame the circle being too small on my sloppy use of the mouse with Paint
I also see the circles are not quite "round" .... ugh

It's the idea that counts
Barry


Smith Charts showing Reflection Coefficient and SWR

Barry K3EUI
 

It seems to me that a logical way of looking at the Reflection Coefficient or the SWR on a Smith Chart is to plot a circle with the perimeter representing all of the impedances that have a given Reflection Coefficient (rho) and its corresponding SWR. Do I have this right now?

de k3eui Barry
West Chester PA


Re: File /NanoVNA PC Software/Screendump/GetScreenSE.exe uploaded #file-notice

Tripp K5TRP
 

You have to use the DiSlord firmware to get screenshots which is here: https://groups.io/g/nanovna-users/files/Dislord%27s%20Nanovna%20-H%20Firmware/NanoVNA%20v1.0.39.rar if you have the 2.8 inch screen use the “H” version and if you have the 4 inch screen then use the “H4” version.


Re: File /NanoVNA PC Software/Screendump/GetScreenSE.exe uploaded #file-notice

BjornA
 

Hi and tnx for a really helpful piece of software!. It works fb with my TinySA but stops half way getting the dump from my NanoVNA. Ver.0.4.5-1-gfbbceca
what can I do to make it work?
73 Bjorn


Re: NanoVNA bricked

w3wte
 

I have seen a lot of the same subject "bricked':. I am passing this on a a possible cause. I my case I upgraded fine with two computers. Then I purchased a new Laptop with only USB3 Ports. It goes to up load and appears to hang. I have duplicated this a couple of times. Just a thought that USB2 ports may be the safer way to go. I may be totally wrong, but just a suggestion.
73, Glenn W3WTE.


Re: Using the nanovna up high (how to avoid dropping it)

Rudolf Schaffer
 

Thank you for sharing this very good idea !

73 QRO,

Rudi, HB9ARI

Le 12.11.2020 à 14:45, DougVL a écrit :
I stumbled across this very helpful page about how to avoid dropping the NanoVNA while up on a tower.
http://www.ok1rr.com/index.php/technical-topics/95-drop-proof-antenna-analyzer
There are _many_ other interesting, helpful (project) pages on this website, too!


Using the nanovna up high (how to avoid dropping it)

DougVL
 

I stumbled across this very helpful page about how to avoid dropping the NanoVNA while up on a tower.
http://www.ok1rr.com/index.php/technical-topics/95-drop-proof-antenna-analyzer
There are _many_ other interesting, helpful (project) pages on this website, too!
--
Doug, K8RFT


Re: Config menu missing, Firmware Ver not readable #calibration #bootloader

Joe (N1MID)
 

Thank you for that. I have a push-button on the right hand side of the nanoVNA that enabled DFU. Hold the button and toggle the power switch to "ON" and a blank gray-ish screen appears. Plug in the USB C cord and the PC recognized the device. The flashing software found it and I was able to upgrade to 0.8.0. Thanks again to all for the support!


Re: SCPI equivalents? REPLY

Jim Lux
 

On 11/11/20 8:29 AM, Antonio Carvalho wrote:
great!
I know, here is not a correctly place to share it, but, do you have idea
how to save in my PC snp (s2p) file from a PNA ?
Thanks for.
http://na.support.keysight.com/fieldfox/help/Programming/webhelp/FFProgrammingHelp.htm


It's the "CALC:DATA:FDATa?" but it doesn't come out as a s2p, necessarily - you'd need to try it and see - the manual says "comma separated numeric". - as I recall, it's basically a collection of lines with values - you need to know, a priori, what the span and spacing is.



Or "TRACE:DATA?"

There's an example in the Examples part of the manual above, called: NA Mode Setup

This example shows how to:

- Create a simple NA Mode setup with 4-window configuration
- Set format, scale, frequency, IFBW, Averaging
- Set triggering to Single
- Read Data
- Clear Averaging



you might also look at:
http://na.support.keysight.com/fieldfox/help/Programming/OLDchmsAndPDFs/FFProgrammingOLD.pdf


Re: SCPI equivalents? REPLY

Sandra Carroll
 

Curiosity,
Does the Nano VNA have enough free program memory to implement SCPI?
I was wondering about this implementation
https://github.com/j123b567/scpi-parser


Re: SCPI equivalents? REPLY

Antonio Carvalho
 

great!
I know, here is not a correctly place to share it, but, do you have idea
how to save in my PC snp (s2p) file from a PNA ?
Thanks for.


Em ter., 10 de nov. de 2020 às 19:49, Jim Lux <jimlux@earthlink.net>
escreveu:

On 11/10/20 9:58 AM, Antonio Carvalho wrote:
Jim, hello. How are you.
Do you have experience with SCPI commands and remote control to VNA
(general one)?
Cheers,
I've done some SCPI to a VNA - lots of SCPI to other instruments.
I know others at work who are doing lots of SCPI to fieldfox
instruments: they want to get both "narrow band" high resolution data,
and wideband data, so they command it to change the span, grab the data,
then change the span, grab the data, etc.





Em qui., 29 de out. de 2020 às 18:52, Jim Lux <jimlux@earthlink.net>
escreveu:

I wonder if there's a semi-standard set of SCPI commands for commercial
VNAs. Then one could make a SCPI : NanoVNA translation layer.

Why?
It might be useful to leverage other systems that have created
abstractions for network analyzers in general.



http://na.support.keysight.com/fieldfox/help/Programming/webhelp/FFProgrammingHelp.htm














Re: Antenna Fundamentals including Nano VNA survey of a few HF antennas at K3EUI

Barry K3EUI
 

Hello Nano VNA folks
Again, thank you for the feedback. Yes, this is what I asked for.

I try to be careful with language, but the slide on antenna "efficiency" was just sloppy.

My main point of putting this together was to look at how to interpret the various graphs that a VNA shows.
I am not an Electrical Engineer, and had no prior experience with the VNA vocabulary.
Six months ago I had no idea what a '"return loss" was, let alone explain why it is positive or negative.

Hams talk about SWR all the time. On nets, I often hear folks say they are worried since their SWR is 1.8:1 at some frequency, and they WANT 1:1.

The book by Walt Maxwell W2DU was fantastic reading for me and taught me a lot about SWR and feedlines and impedance.

I wanted to start my presentation with some basic antenna characteristics, like resistance, reactance, impedance and phase. Then branch into the VNA world to discuss how these parameters can be measured at least with reasonable accurately at HF with a $50 gadget and free software.

So that was my goal. I am adding some slides on "reflection coefficient" (rho) in tems of what various values of rho look like on a Smith Chart. Rho of zero is just one point on that graph: R = 50 ohms and zero reactance (with 50 ohm coax). So if you visualize the Smith Chart as a Dart Board, and the center is where you are aiming, then a SWR of 1:1 is only at the exact center of the dart board (Smith Chart).

So if ou miss the Bull's Eye, your reflection coefficient is bigger than 0. And how much you miss will indirectly tell you LOTS of information. The perimeter of the Smith Chart is a reflection coefficient of 1. Of course, that is just awful. Reflection Coefficient (0-1) leads to RETURN LOSS (dB) and that leads to SWR.
I think I now have an 8th grader understanding of all of these terms now.

What puzzled me was how to interpret the PHASE curves on simple one-band dipoles.
At resonance, reactance is zero (I get that) and PHASE crosses over from neg to pos.
WHY? If a ham (non engineer) can explain that in a few sentences, then that is a pretty good understanding of the concept of resonance. Of course, these are measurements made in my shack, about 100-150 ft of RG213 from the antenna being measured.

I find most hams (I talk with) think the SWR changes with feed line length (other than attenuation).
Many hams (I talk with) do not see why impedance changes with line length if Z is other than 50 ohms.
These can be easily confused by most of us in our (casual) discussions.
Running around 180 degrees in a Smith Chart was a real "eye-opener" for me, personally.

I noticed that QST article last May had a quick "review" of the Nano VNA but did not go into any detail explaining the relationships of the various graphs. Perhaps a second article for QST would help us non-engineer types see the value of a $50 VNA so we can adjust our antennas to work better.

Again, from a rookie at VNA language (but a ham for over 60 years)
Thank you. This IO group obviously has some very talented hams.

Barry k3eui


Re: NanoVNA bricked

ON7IVE Ive
 

Hi Peter,

I had a working NanoVNA that I wanted to update, but it also didn't work with DfuSE due to only STM32 BOOTLOADER showing up in the Win10 device manager.
The STM32CubeProgrammer indeed did the trick (with only the usb connection!)

Steps I used with the Nano in programming mode (shortened pins):
- Connected the Nano to the pc via the usb cable, switched the device on, started STM32CubeProgrammer software.
- Switched the connection (Tab in the upper right corner) from ST-LINK to USB, and connected.
- In the 'Memory and File Edition' menu, I've set Size to 0x20000, Data Width to 8 Bits (Address of 0x0800000 showed already) like mentioned by QRP RX in this topic.
- Read the original data and saved it as backup (.bin format).
- Switched to the 'Erasing & Programming' menu, I ERASED the Flash Memory and wrote the firmware that QRP RX left in this topic.

Ended up with a working NanoVNA that has 4 traces now, and has a higher resolution! ('NanoVNA GEN111.TAOBAO.COM' showing on the splash screen when starting up).
(I did get it bricked when not erasing the flash memory before re-programming).

Thx for the solution QRP RX and Peter!
73 from happy ON7IVE


Re: A guide for absolute beginners #docs #learning #nanovna-h #newbie #tutorials

Danny K5CG <k5cg@...>
 

That was 19 words. :)


Re: Config menu missing, Firmware Ver not readable #calibration #bootloader

Larry Rothman
 

Joe,
You have a very old release of firmware. Read up on how to place your unit into dfu mode by shorting the boot 0 pins and then flash the latest firmware.You'll need to install the dfu utility or if using Linux the flashing is done with different commands. 
Please download and read one of the many user guides in the forum file section and watch some of the YouTube videos on flashing. 
Note: you can flash H FW on your unit but not H4 or F versions. 
Good luck. 


On Tue, 10 Nov 2020 at 2:23 PM, Joe (N1MID)<joeslushy@gmail.com> wrote: adding a command line "info" copy and paste


Re: Config menu missing, Firmware Ver not readable #calibration #bootloader

Gyula Molnar
 

Hi Joe,

Welcome to nanoVNA users.
Indeed: he who dares wins. For someone who has a problem and doesn’t know the solution, it’s hard to articulate what their problem is.
The interviewer knows best what he is wondering about. Feel free to use the descriptions in the wiki and files folder.
If you’ve messed something up, you don’t have to panic because there’s some solution, you just don’t know about it.

Successful use for you

73, Gyula HA3HZ
--
*** If you are not part of the solution, then you are the problem. ( http://ha3hz.hu/ ) ***


Re: Config menu missing, Firmware Ver not readable #calibration #bootloader

Joe (N1MID)
 

Nothing ventured, nothing gained. I did a blind firmware update to get to 0.8.0 and now all is right with the nanoVNA. I have a config button. The risk was worth the reward and I appreciate those who've gone before me and produced the following guides:
Upgrade process: https://github.com/ylabrj/NanoVNA_Load_Windows10
Where to get firmware: https://github.com/ttrftech/NanoVNA/releases
Shell commands (via Putty): https://groups.io/g/nanovna-users/files/NanoVNA_Console_Commands_Dec%209-19.pdf


Re: Config menu missing, Firmware Ver not readable #calibration #bootloader

Joe (N1MID)
 

adding a command line "info" copy and paste


Re: SCPI equivalents? REPLY

Jim Lux
 

On 11/10/20 9:58 AM, Antonio Carvalho wrote:
Jim, hello. How are you.
Do you have experience with SCPI commands and remote control to VNA
(general one)?
Cheers,
I've done some SCPI to a VNA - lots of SCPI to other instruments.
I know others at work who are doing lots of SCPI to fieldfox instruments: they want to get both "narrow band" high resolution data, and wideband data, so they command it to change the span, grab the data, then change the span, grab the data, etc.



Em qui., 29 de out. de 2020 às 18:52, Jim Lux <jimlux@earthlink.net>
escreveu:

I wonder if there's a semi-standard set of SCPI commands for commercial
VNAs. Then one could make a SCPI : NanoVNA translation layer.

Why?
It might be useful to leverage other systems that have created
abstractions for network analyzers in general.



http://na.support.keysight.com/fieldfox/help/Programming/webhelp/FFProgrammingHelp.htm






Config menu missing, Firmware Ver not readable #calibration #bootloader

Joe (N1MID)
 

Hi all. Im new to my nanoVNA, but I've been browsing the Group. First thing to do is calibrate the touchscreen. I think I am missing some key functionality, the Config menu is missing. So, that brought me to think, perhaps the FW was corrupted. I've browsed around on the wiki and topics and could not find anyone with a similar problem. I went looking for what firmware I was on and discovered that its under the missing config menu.
Ok, perhaps NanoVNASaver has the firmware, right? Download, plug in, scan ports, connect and I see data points flowing in, Great. I picked the About button in Saver and the FW is v0.0.0. That's probably wrong. The CMD line for nanoVNASaver is attached.
So, what is a newbie to do? All thoughts are welcome.

3441 - 3460 of 21871