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Hi Arno,

I visited your page. Very nice construction on the mag loop. I see 20 to 30 dB return loss, between the VNA on the web page and the new unit in the photo. Quite well done. I have a few questions.

Do you switch the VNA out during transmit? I assume your loop is used in the Tx mode? How do you protect the VNA input? What power are you running? Are you using a relay to switch around the VNA for protection?

Finally, the radiation R of the loop vs. its loss. Curious about the mag loop antenna efficiency.

On your question... any ideas for an application. I saw a cute photo that Larry Goga sent me. He posts on this forum. He took one of the classic antenna tuners and I assume did a photo shop mod of the front panel. He removed the cross needle forward and reverse power indicators and replaced that meter movement with a VNA in the S11 mode. So in essence the old SWR meter indicator could now be afforded a VNA display. Auto tuning the S11 marker to the lowest point in the SWR curve would be a nice firmware update.

Thanks! 73' Alan W4AMV

Hi Arno,
a good idea! In My EU1KY analyzer I have implemented a function to automatically search the frequency with the best SWR, or the minimal S11.
For the makers of the nanoVNA software this is no problem.
A good improvement.
Best regards,
73, Wolfgang, DH1AKF

In all honesty I was not sure if the approach I was following to determine imperfections in a calibration kit made sense. Various wise people on this group have given me hints which, due to lack of knowledge on my side, I probably failed to understand.
So I decided to to some more investigations.
I used THREE different VNA's
VNA 1: NanoVNA (we all love)
VNA 2: Home build nanoVNA equivalent.
VNA 3: Home build 3 GHz VNA (uses same type of resistive bridge and measurement principles as nanoVNA but it does not use overtone mode)
and ONE calibration kit and ONE set of cables.
I measured on all VNA's the same calibration kit directly on the connector for calibration, the same 1 meter RG58 cable with OSL and the same 30cm semi rigid cable with OSL
All measurements where done till 900MHz. The calibration kit is assumed to be perfect. No compensation factors where used.
Any difference seen between these measurements should come from the difference in VNA's
After calibration all three VNA's show for the calibration kit a perfect calibration, no difference is seen.
In attached pictures you will see the calibrated plots of the measurements on the three different VNA's of the logmag S11 of the long cable (RG58) and the medium cable (semi rigid) with open and short at the end.
The only difference between the three pictures is the VNA. Cables and calibration kit are the same.
It is safe to conclude there are substantial differences between the three VNA's
First picture: VNA 1 (nanoVNA) seems at low frequencies to have a Z0 that best matches the impedance of the cables but shows a substantial deviation above 600MHz
Second picture: VNA 2 (home build VNA) has a bit worse Z0 match and seems to have a S11 open of both cables that goes off track above 800MHz
Third picture: VNA 3 (3GHzVNA) becomes very noisy above 550MHz (need to investigate why as this is new) but the oscillations of the logmag S11 show no sign of substantial deviation apart from gradual increase in amplitude and the cable loss in dB stays nicely linear with frequency
This comparison underpins my initial assumption that the nanoVNA needs a bridge error model to correct the differences (in particular above 300MHz) and until these threeVNA's (with their individual bridge error models) give the same measurement results I better not try to calculate calibration kit error parameters
Feedback is welcome
--
Erik, PD0EK

Tomorrow I'll get busy with Console Commands
(Putty on my Ubuntu laptop should do the trick)
and will go through more of the Wiki and Files stuff.

PuTTY works, but if your Ubuntu already has Python,
then this script enables interacting directly from bash:


.. after edits for your path and serial port.

By adding to your ~/bash_profile:
ch ()
{
python /path/to/nVcmd.py "$*"
}

Then you can invoke, e.g.:
$ ch help
Commands: help exit info threads version reset freq offset time dac saveconfig clearconfig data dump frequencies port stat gain power sample scan scanraw sweep test touchcal touchtest pause resume cal save recall trace marker edelay capture vbat transform threshold color vbat_offset
$ ch trace
0 LOGMAG CH0 10.000000000 8.000000000
1 LOGMAG CH1 12.000000000 8.000000000
2 SMITH CH0 1.000000000 0.000000000
$ ch marker
1 50 57000
$ ch frequencies > freq
$ ch data 0 | paste freq - > my.s1p

Ok, now that I know you're running Linux, please read the wiki notes on device access if you're going to flash new FW. A number of forum members here are also running *nix boxes so if you run into issues...ask.?
Cheers
Larry



On Sun, 3 Nov 2019 at 6:50 AM, l49mantuano@...<l49mantuano@...> wrote: Thank you Larry and everybody else!? There is no Config button. Tomorrow I'll get busy with Console Commands (Putty on my Ubuntu laptop should do the trick) and will go through more of the Wiki and Files stuff.
Thanks again to all for the warm and helpful replies.. I'll keep you informed..
ciao
lm

Thank you Larry and everybody else! There is no Config button. Tomorrow I'll get busy with Console Commands (Putty on my Ubuntu laptop should do the trick) and will go through more of the Wiki and Files stuff.
Thanks again to all for the warm and helpful replies.. I'll keep you informed..
ciao
lm

Mel,
I used a commercially made HP 50 ohm termination as my standard until David Taylor pointed out that even though it was manufactured by HP its s-parameter specs were lukewarm at best.
[]
- Herb
=======================================

Herb,

It wasn't me who commented on your HP termination. Must have been another David!

Cheers,
David
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv

just look to see how well behaved the LOGMAG signal is on an open port?

on closed (with 50-ohm load)

Bridge is most sensitive and reflected signals are smallest (so noise is a larger portion)
when terminated by 50 Ohm calibration load.

One thing I noticed in my readings is that the 2-trace unit is referred to as
"antenna analyser"

While limited to 2 traces, your firmware does support that second port,
so is truly a VNA. To find items 'hidden' in touch screen menu, see:


Other introductory material:
/g/nanovna-users/wiki/User-Guides

Have built a magnetic antenna for the 80meter band as shown on my homepage .
As the antenna has an excellen high Q (bandwidth aro 9kHz) it shows a sharp dip in S11 return loss.
To integrate the analyzer I removed the battery, supplied 5V through USB and bridged the ON/OFF switch
set in OFF position with an external relais contact.
Found out that the 5V have to be present before switching to ON or closing the relais contacts, otherwise
the unit won*t start at all. It then draws about 110mA of supply current. (An empty batterie would increase
the current to beyond 700mA, that's why I removed the battery)

The instrument setting is fix and saved to SAVE0, so it starts always with this setting.
See the picture.

Anyone having good advices or ideas for this application, or already done something similar?

Great would be an extended marker feature to direct display the frequency of the dip in S11.
--
Arno DK3SS

Hi Luigi,To determine the version, touch the display to bring up the menu.?Does the menu show Config as the least bottom button?If there is no Config button you most likely have version .0.2.x firmware.?If there is a Config button, press it so it turns green and release.?If one of the other buttons is selected it the menu disappears, you will need to do a touchscreen calibration but first, try to get to the config menu.?In the config menu there should be a Version key.?
Another way to determine the version is through the Console Commands.?The NanoVNA will need to be connected to your PC.?What are you running?? For Windows, install the STM serial drivers located in the files section of the forum. Check the wiki's firmware section on what to install.?You will also need a serial terminal emulator. I use Teraterm. Putty is ok but slightly more involved to config. Since this is a usb device, the speed settings are irrelevant.?
Once in console mode, you will get a CM> prompt.?Enter:? helpThat will show you all the commands. Please refer to the Console Commands document in the files section of the forum.?There are two commands you want...version and infoInfo will show you all the version information in the newer firmware releases.?The version command will show you the basic version number.?
Once you have all that, you can print a copy of the user guide I formatted for clean printing and you're ready to start playing.?
Enjoy!
... Larry


On Sun, 3 Nov 2019 at 1:00 AM, l49mantuano@...<l49mantuano@...> wrote: G'day!
New to nanoVNA and new to groups.io, so please bear with me..
got my unit three days ago from Aliexpress. It's white, no lizard logo, no RF shielding, no idea what FW it's running and I get only two traces, blue and yellow.
I've done a fair bit of reading and I'm still very confused.? One thing I noticed in my readings is that the 2-trace unit is referred to as "antenna analyser" and has better screen resolution?
I'm not ready to start playing with the different FWs.
Antenna testing is all I want to do at the moment but later I would like to be able to play with filters and other RF (VHF & UHF) things.
I'll keep on reading, but in the meantime could some kind soul point me in the right direction re finding out exactly what I've got?
Thanx & regards,
Luigi M.

On 03.11.2019 07:00, l49mantuano@... wrote:

G'day!
New to nanoVNA and new to groups.io, so please bear with me..
got my unit three days ago from Aliexpress. It's white, no lizard logo, no RF shielding, no idea what FW it's running and I get only two traces, blue and yellow.
I've done a fair bit of reading and I'm still very confused. One thing I noticed in my readings is that the 2-trace unit is referred to as "antenna analyser" and has better screen resolution?
I'm not ready to start playing with the different FWs.
Antenna testing is all I want to do at the moment but later I would like to be able to play with filters and other RF (VHF & UHF) things.
I'll keep on reading, but in the meantime could some kind soul point me in the right direction re finding out exactly what I've got?

What you have will do the job.

However, new firmware offers new features and bugfixes. It is nothing you must have but it is good to have.

Two track firmware does not have higher resolution. It just uses bigger font so text is more readable. but as memory space is limited, space reserved for two traces data is reassigned for big font. Other than that it is the same functionality. And for usual measuring two tracks are enough.

There is actually one firmware clone that keeps four tracks and offers bigger font. It freed memory by removing Chinese font.


--
73,
Pedja YT9TP

Checkout:

Hi Luigi,

welcome to the group. There really is a lot of information and you have to select what you are curious about.
In the group you have access to the Wiki and Files folders, where you can decide whether you are interested in the subject or move on. There are several websites where some information can be found, if you have any further questions, please ask.

Good job!
73, Gyula HA3HZ

G'day!
New to nanoVNA and new to groups.io, so please bear with me..
got my unit three days ago from Aliexpress. It's white, no lizard logo, no RF shielding, no idea what FW it's running and I get only two traces, blue and yellow.
I've done a fair bit of reading and I'm still very confused. One thing I noticed in my readings is that the 2-trace unit is referred to as "antenna analyser" and has better screen resolution?
I'm not ready to start playing with the different FWs.
Antenna testing is all I want to do at the moment but later I would like to be able to play with filters and other RF (VHF & UHF) things.
I'll keep on reading, but in the meantime could some kind soul point me in the right direction re finding out exactly what I've got?
Thanx & regards,
Luigi M.

On Sun, Nov 3, 2019 at 06:38 AM, Joe St. Clair AF5MH wrote:

just look to see how well behaved the LOGMAG signal is on an open port?

on closed (with 50-ohm load)

So is that all there is to judging the effectiveness of shielding - just look to see how well behaved the LOGMAG signal is on an open port?

gin & pez;

It has been a productive day for me today. I just completed getting "open-watcom-f77-win32-1.9" installed and running, and I was able to successfully compile the files from DERDEI20191001, run the executable, and produced the PDEIS and RDEIS uncertainty output files, several 3D object files, and multiple others. I now have only to bridge the interface from the Fortran output into wxMaxima to enable GNU plotting, and I soon will be able to replicate your work from start to finish.

--
73

Gary, N3GO

Hello Pierre,
I would try QRP RX's firmware. It is located here:


HTH,
Marco

Is there a firmware that will run properly with the latest NanoVNA-Saver and is able to go up to 1500mhz.. ( in fact up to 1GHZ would be more then enough)

And can you please point to where it is just in case ;-)

Pierre
VE2PF

Note: If you still have the original software installed then the freq span is 50KHz to 900MHz (300MHz without using harmonics).

- Herb