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Hi Ernst,

When the calibration is complete does the side screen show all the elements of the cal. I assume you are doing an ISOL cal as well as a THRU cal despite perhaps not interested in a S21 measure.

Alan



________________________________
From: [email protected] <[email protected]> on behalf of dk1vi <dk1vi@...>
Sent: Friday, July 5, 2019 3:57 PM
To: [email protected]
Subject: Re: [nanovna-users] Strange peaks in S11 with load

[Edited Message Follows]
[Reason: Correction of calibration range]

Flashed firmware nanoVNA_800_ch_20190705.dfu. Unit still initialises from 50k to 900M.
I performed calibration from 50k to 800M, but behavior is strange: there is always an offset of abt -24dB on displayed mag S11 during calibration process..
Now the plots are smooth without spikes but calibration does not work as expected.
Short gives 0dB but open shows -9dB. With "Correction" switched, open and short both have S11 -24dB.
Ernst

Flashed firmware nanoVNA_800_ch_20190705.dfu. Unit still initialises from 50k to 900M.
I performed calibration from 50k to 800M, but behavior is strange: there is always an offset of abt -24dB on displayed mag S11 during calibration process..
Now the plots are smooth without spikes but calibration does not work as expected.
I made calibration with Software on PC was connected.
Recalibrating with PC disconneted give good results. However with load, mag S11 is very rugged. When using "Correction" line gets smooth, but with short and open, there is -25dB offset. Strange.
Ernst

Just found new firmeware dated 20190705 on the well known google drive.
Ernst

Folks,
There appear to be two locations on GitHub for the nanoVNA firmware:
original:
hugen:

Both appear to be old and haven't been updated in some time.

It would be great if Hugen would provide a URL link to the opensource code he is currently maintaining for this device or at least make some commits to the repository.

Thanks,
Larry

May I suggest that when the nanoVNA boot screen occurs, THE BOOT MESSAGE HAS THE FIRMWARE VERSION AND DATE AND TIME. THIS IS WHAT THE BIG BOYS DO.

________________________________
From: [email protected] <[email protected]> on behalf of sites.online@... <sites.online@...>
Sent: Friday, July 5, 2019 1:02 PM
To: [email protected]
Subject: Re: [nanovna-users] Strange peaks in S11 with load

On Thu, Jul 4, 2019 at 05:55 PM, <hugen@...> wrote:

hugen

Hello hugen, thanks for your hard work.
Where can we track your FW releases?
Cheers!

LL

On Thu, Jul 4, 2019 at 05:55 PM, <hugen@...> wrote:

hugen

Hello hugen, thanks for your hard work.
Where can we track your FW releases?
Cheers!

LL

is there anyway to know if this one is a bad clone ? This is what I have placed an order for but not shipped yet. I can still cancel it. Thanks !

That's all there is to it. Connect the open , press open. Connect short, press short etc.
Frank

Hello hugen,
I am very glad that you are taking care of my problem. So I do not have to send my unit back.
Thank you in advance for your efforts.
Ernst

Two bad clones have been found, they have failed to understand the role of bridge and shielding, and made some bad modifications to facilitate manufacturing.

Hi Siggi/Hugen,
I have managed to place an order using the Chinese taobao site, which was
rather interesting as I cannot read Chinese at all :)
Hopefully you got my order in your shop Hugen !

I found a few things that were different to what I expected so maybe this
will help:
* You can enter your address before starting the purchase process. It is
under your username then account.
* Enter your address all on one line seperated by commas. If you hit enter
after each line it will show a red error.
* Use the standalone google translate page to translate your country name
into Chinese Simplified. Then you can recognise the Chinese characters when
you need to select it.
* You need to click the image of the NanoVNA which then switches the price
to 299, shown in the Red circle in Hugen's reply - the range in prices are
for the various adapters pictured. Only one option is the VNA itself.
* You need to select overseas in the option just above those little
pictures too. Googles translate says "Shanghai to the country". Pick
Overseas and then your country.
* Google Chrome tries to translate by default, which breaks the "Buy"
button so you need to turn off translate when you get to this point or use
Firefox or something else.
* Use the standalone google translate for the parts that don't make sense.
Copy paste.

Anyway I thought you deserved some reward for your work Hugen. I have no
idea if I have actually purchased it correctly, time will tell :)

Cheers,
Roger

Thank you, Siggi

You can try switching the regional options of Taobao.

On Fri, Jul 5, 2019 at 12:40 AM, dk1vi wrote:

Hi,
got my nanoVNA today (black edition from banggood). Included was a set of cal
standards: load, open, short and through with 2 SMA cables. As far I can
judge, they are good quality. I measured Rl to be better -40dB with my old hp
8410 VNA @900MHz.
No battery was included. Does someone have a more detailed specification? I
know it is 400mAh, but what technology (NiMH, LiPo etc.) and what voltage? I
will try to find a supplier preferably in Germany.

No problems with NanoVNA 1.03 working perfectly on Windows 10 x64.

However after calibration I see strong and very annoying peaks in S11 with
load connected. The peaks at approx. 300MHz and its harmonics jump up and down
tens of dB. See picture enclosed. So I am very disappointed aboout this.
The peaks are independent of the laptop connected. Any ideas how to cure?

Regards Ernst

Hello dk1vi ,

Peaks occur because si5351 is working at the limit，I will update an 800MHz firmware later to improve this problem.
Thank you！

hugen
gen111.taobao.com

I just had the same idea. Scan from 50MHz to 200MHz for example and the plots look good.
Tomorrow I will inspect the PCB and see if all components are soldered properly.
Ernst

Understood Ernst. Good observation. It will be of interest if other users report this situation. I assume if you do a cal that eliminates those frequency points, that is select a stimulus frequency range that does not include those edge frequency points, the cal looks good.

________________________________
From: [email protected] <[email protected]> on behalf of dk1vi <dk1vi@...>
Sent: Thursday, July 4, 2019 7:19 PM
To: [email protected]
Subject: Re: [nanovna-users] Strange peaks in S11 with load

[Edited Message Follows]

Alan,
the peaks are always on the edges of the three frequency ranges 52k-300MHz, 300-600MHz and 600-900MHz. So I think it has somethoing to do with the timing of range switching.
Probably the hardware designer has an idea.
There is no poor contact of the load to the SMA connector.
Ernst

Alan,
the peaks are always on the edges of the three frequency ranges 52k-300MHz, 300-600MHz and 600-900MHz. So I think it has somethoing to do with the timing of range switching.
Probably the hardware designer has an idea.
There is no poor contact of the load to the SMA connector.
Ernst

Hi Ernst.

I would check with care that the SMA terminations during cal are all secure. I would like to use a torque wrench designed for proper tightness for each piece. However, these connectors on the nanoVNA are going to take a beating over the long term. I suggest you get some connector savers to help protect the SMA connectors on the instrument. Then you can provide secure tightness of the cal units. It would appear that there is an issue in the CAL. Alan

You may wish to check your sNp file. There could be an interpolation issue that is creating the discontinuity. I have seen such problems in "professional" SW like ADS and Microwave Office.

________________________________
From: [email protected] <[email protected]> on behalf of alan victor <avictor73@...>
Sent: Thursday, July 4, 2019 6:52 PM
To: [email protected]
Subject: Re: [nanovna-users] Strange peaks in S11 with load

Good day,

Ok, I just took a measurement after cal with the nanoVNA and then captured that data using their SW, There are two measurement .jpg attached. The first is their 50 termination after cal. Yes, nice cal. The second is a quality 50 ohm termination. Yes, the return loss at 900 MHz is about 18 dB. This is an issue that is part of another discussion. However, focus on your issue, I do not see their SW causing spikes in the data.

Alan



________________________________
From: [email protected] <[email protected]> on behalf of amirb <amir.borji@...>
Sent: Thursday, July 4, 2019 6:40 PM
To: [email protected]
Subject: Re: [nanovna-users] Strange peaks in S11 with load

no the OP, dk1vi, has his nanoVNA.
I am waiting on mine



On Thu, Jul 4, 2019 at 02:25 PM, alan victor wrote:

You are waiting on the unit to be shipped. So I assume this is a measurement
of another VNA using whose 50 ohm termination? Is the issue you are raising
the software or the hardware? I can input a touchstone file from another
instrument and a "good" 50 ohm termination and plot log mag s11 and see if I
detect spikes (due to interpolation?) in the plotted data.

Alan

________________________________
From: [email protected] <[email protected]> on behalf of amirb
<amir.borji@...>
Sent: Thursday, July 4, 2019 5:11 PM
To: [email protected]
Subject: Re: [nanovna-users] Strange peaks in S11 with load

this looks awful !
I am still waiting for mine to be shipped but this result got me
scared/disappointed :-(

Hi Alan,
your plots look excellent, I wish mine would look same. The peaks are not related to the nanoVNA software V1.03. I see the peaks when I use the nanoVNA not connected to the laptop.
Ernst

Good day,

Ok, I just took a measurement after cal with the nanoVNA and then captured that data using their SW, There are two measurement .jpg attached. The first is their 50 termination after cal. Yes, nice cal. The second is a quality 50 ohm termination. Yes, the return loss at 900 MHz is about 18 dB. This is an issue that is part of another discussion. However, focus on your issue, I do not see their SW causing spikes in the data.

Alan



________________________________
From: [email protected] <[email protected]> on behalf of amirb <amir.borji@...>
Sent: Thursday, July 4, 2019 6:40 PM
To: [email protected]
Subject: Re: [nanovna-users] Strange peaks in S11 with load

no the OP, dk1vi, has his nanoVNA.
I am waiting on mine



On Thu, Jul 4, 2019 at 02:25 PM, alan victor wrote:

You are waiting on the unit to be shipped. So I assume this is a measurement
of another VNA using whose 50 ohm termination? Is the issue you are raising
the software or the hardware? I can input a touchstone file from another
instrument and a "good" 50 ohm termination and plot log mag s11 and see if I
detect spikes (due to interpolation?) in the plotted data.

Alan

________________________________
From: [email protected] <[email protected]> on behalf of amirb
<amir.borji@...>
Sent: Thursday, July 4, 2019 5:11 PM
To: [email protected]
Subject: Re: [nanovna-users] Strange peaks in S11 with load

this looks awful !
I am still waiting for mine to be shipped but this result got me
scared/disappointed :-(