Hi folks,

I need help to know if my newly bought (few months ago) VNA V2 Plus 4 from Tindie is good unit or not. When any antenna connected it do not draw the SWR graph. I am sure it is a good unit and as a new user I am doing something wrong.

Initially I just turned on the device and checked if the menus are working and device respond to touch screen and found OK. For a month and a half was busy and did not have time to play with the device. From last 4 to 6 weeks, I gone through the docs available in the Wiki written by Martin Savacoi (9A2JK) and the one found online written particularly for this unit by Bill Ruggirello (NC4BR). I still think I am doing something wrong that after the calibration done as described below, I am still doing something wrong that when an antenna is connected it do not display SWR graph.

Here what I did for the calibration.

-Turn on the unit.
-Display > Channel: selected Ch0 Reflect
-Frequency set = 100Mhz ~ 900Mhz.
-Display > Trace > 0 is ON.
1, 2, 3 are OFF and grayed out.
-Display > Format : SWR
-Display > Scale > Scale/Div = .25 X1
-Calibrate > Calibrate :
Connected first the "OPEN" standard on Ch0, then pressed Open. Had a check mark and show on the left hand side "O"
Then connected "SHORT" standard on Ch0, pressed SHORT. Had a check mark and show on the left hand side "S"
Then connected "LOAD" standard on Ch0 , pressed LOAD. Had a check mark and show on the left hand side "L"
Then connected nothing on Ch0 , pressed THRU. Had a check mark and show on the left hand side "T"

I saved the calibration in slot 0 (Zero).
Set the range on memory 4 for 144 MHz to 148MHz (and other ranges in other slots).
I connected my Diamond HT antenna "SRH230" and the VNA do not show any graphs.

Attached are the pictures I have taken. Please open the pictures as I have placed some handwritten notes on them. What I am doing wrong? Anyone can help?

Thank you,
Sohail, VE3ITU.

Good Day!

The SWR Graph is indeed showing, only all of the values it is calculating are out of the range of the current display.   You said you set the SWR to .25 per division.  For now, change that to 2 per division and you should see the SWR come into view.

You described that you performed a calibration and then saved that to memory 0, which sounds correct.  You then when on to set a memory change in channel 4.   Did you calibrate the unit again?  If not, you should.   Every time you make a frequency range change you must recalibrate.   Old calibrations settings become invalid when the frequency range changes.

Did you run the self test routines, and did they all pass?

Enable the smith chart for channel 0 as the active trace.  Turn off all others.  Perform a calibration.  After a calibration, and now with the 50-Ohm load connected to Ch 0, there should be a single single dot dead-center in the middle of the smith chart  Is that what you see?  Replace the 50-ohm load with the open standard.  You should have a single dot on the display far right on the horizontal center line.  Is that what you see?   If you now install the short standard on Ch 0 port, does the dot move to the far left of the horizontal center line?  Is that what you see?

Using the smith chart with the SOL standards is a great way to visualize if your unit is calibrated correctly for the range of test.   Please check this and post a pictures of the smith chart with each of the three calibration standards connected for the range of test.   Then, turn on the SWR display in addition to the Smith chart while you have the 50 ohm load connected to Ch 0.  Post a picture of that as well.    In this last picture we are expecting to see a solid straight line along the bottom of the display.

Hi Michael,

Thank you for the tips and guidance. I started as you mentioned but an urgent family matter came in between and I just left all calibration and setting in the middle. Will do it tomorrow and will post the results.

Thank you
Sohail VE3ITU

Maybe this setting will help: Display-> AVG: Set to 2 times

Regards

Hi Michael,
I started from the scratch again. It seems it is doing something correct this time.  I am listing my steps exactly I did one step at a time so you can follow me.
-Turn on the unit.
-Battery is already in the unit.
-But connected with the laptop USB port to keep the battery charging.

-Calibrate > Reset All
***Pic-001

- Back

- Dis play > Channel: selected Ch0 Reflect (Already selected, has check mark)
-Trace > 0 is ON (has a check mark)
1, 2, 3 are turned OFF and grayed out by clicking twice on each.

- Back
-Format : Smith  (one dote appearing on the extreme Right hand side. No calibration standard attached with any port ).

***Pic-002

- Tap on the screen > Back > Back (twice to reach to main menu)
-Stimulus > Start > 144 M  ----> Start showing SOLT in Red. one dote appearing on the extreme Right hand side.
-Tap on the screen > Stop 148 M
-Tap on the screen > Back
-Calibrate > Calibrate :

Note : I see now OPEN, SHORT, LAOD and THRU already have Check marks.
On the left hand side it shows SLOT in RED.
I do not understand how come there are check marks on all 4 while I have not yet started calibrations
and no "Standards" connected with the Nano VNA.

-Connected "OPEN" standard on Ch0, then pressed Open. Take few seconds, Gray colour become dark Gray colour and then return to normal Gray colour. (Remember the check mark is already there. And SOLT displaying in Red on the Left hand side.

-T hen connected "LOAD" standard on Ch0 , pressed LOAD. Take few seconds, Gray colour become dark Gray colour and then return to normal Gray colour. (Remember the check mark is already there. And SOLT displaying in Red on the Left hand side.

-Then connected "SHORT" standard on Ch0 , pressed SHORT. Take few seconds, Gray colour become dark Gray colour and then return to normal Gray colour. (Remember the check mark is already there. And SOLT displaying in Red on the Left hand side.

-Then connected one connector of the Blue SMA connector to Port 0 and the other connector of the Blue cable to Port 1 , pressed Thru. Take few seconds, Gray colour become dark Gray colour and then return to normal Gray colour. (Remember the check mark is already there. And SOLT displaying in Red on the Left hand side.

-Dis connected the cables.

-SOLT now showing in GREEN (all the Graph going crazy in Smith Chart).

***Pic-002
-Save > SAVE 0

Back > Back > Touch on the screen, to disappear the main menu.

-Connected "OPEN" Standard.
***Pic-003 showing dot on the Right side. Lot of graphs moving.

-Connected "LOAD" Standard.
***Pic-004 showing dot in the middle with more then one graphs.

-Connected "Short" Standard.

***Pic-005 showing dot in the left with more then graphs.

/////Disconnected the "Standard".

-Back

-Format : SWR

****Pic-006

Connected Diamond HT antenna "SRH230" (Tri band Antenna 144/220/440 MHz)
***Pic-007

When touching the antenna, graphs changes. In order to have antenna in the air up ward, put the Nano VNA in standing position.
***picture-008

-Graph is upside down.
-Flip the display
***picture-009

-Display > Scale -Reference Position = 4
***Pic-010

-Display > Scale > Scale/Div = 2 X1

***Pic-011

-Back > Back
-Calibrate
-Save > SAVE 4
***Pic-01
Please confirm if everything is done correctly. I have few questions that I will ask later.

Sohail VE3ITU.

Hi Tonpijpers,

Here is the picture with settings Display-> AVG: Set to 2 times. Seems don't make much difference. Anyone else see what need to make changes to see nice graph. I tried between 144.000 and 144.200 with no difference the way the graph is displaying.

Thank you.
Sohail VE3ITU.

Maybe its help you with the following pdf. https://nanorfe.com/images/V2Plus4_Manual_NC4BR.pdf

Good Day.

The fact that your Smith Chart does not show three nice clean dots at the open, short and 50-ohm locations of the resistance axis after calibration is a sign that your unit is not calibrated/calibrating properly.     Immediately after a calibration that chart should be nice and clean with no gibberish, hence the reason I wanted to see it.   Your images are telling us there is a problem.

When you start a fresh calibration there should be no SOLT text on the left-side of the screen and no checkmarks next to the Open, Short, Load, and Thru menu choices on the calibration menu.     The fact that these did not go away after the Reset All option is highly concerning.   Those items absolutely should go away when either Reset and Reset All are pressed.

While I know you have used the Reset All button, have you tried just the Reset button to see if SOLT and the checkboxes go away?     If not, please try.

Have you changed the firmware since you have had the unit?  If so, did it seem to work correctly before?     If not, perhaps reloading the firmware could be a help.

What firmware is your unit running?  Mine is running ‘git-20210530-412578c’ with a Nov 3, 2021 12:34:01 compile date.   Perhaps loading the same version that mine is running could make a difference.

Thank you.

Mike C.

On 3/9/2022 3:11 AM, tonpijpers via groups.io wrote:

> Maybe its help you with the following pdf.
> https://nanorfe.com/images/V2Plus4_Manual_NC4BR.pdf
>

Hi Tonpijpers,
Thank you for the link. Before I posted my first message I already found and downloaded *Bill Ruggirello (NC4BR)* user guide that you are referring.

I also gone through the Wiki  section of the other group " nanonva-users ". There is a detail user guide written by *Martin Savacoi (9A2JK)*.I have gone through that too.

Sohail VE3ITU.

Good day Michael,

Thank you for the feedback. My firmware version is same as yours. If  you look my very first message, I posted the picture of the firmware as well. You will find it is same. I will reinstall the same firmware and test again.

Thank you,
Sohail VE3ITU.

Hi Michael,

I updated the firmware from ‘ git-20210530-412578c’ with a Nov 3, 2021 12:34:01 compile date to 20211227 dated 27 Dec 2021. I still have the same issue. Please see my notes below.
***Pic 001

Please note that all steps in RED (crossed) are the one I did in my previous posting dated Mar 7, 2022 (see one of my email above) but I skipped these steps this time. The effect is that I do not see anymore the OPEN, LOAD, SHORT and THRU is already checked before the calibration as I saw it last time.

- *Calibrate* > Reset All
- Back

- *Dis* *play* > Channel: selected Ch0 Reflect (Already selected, has check mark)
-Trace > 0 is ON (has a check mark)
1, 2, 3 are turned OFF and grayed out by clicking twice on each.

- Back
- *Format* : Smith  (one dote appearing on the extreme Right hand side. No calibration standard attached with any port ).

- Tap on the screen > Back > Back (twice to reach to main menu)
*-Stimulus >* Start > 144 M  ----> Start showing SOLT in Red. one dote appearing on the extreme Right hand side.
-Tap on the screen > Stop 148 M
-Tap on the screen > Back
-Calibrate > Calibrate :

Note : I see now OPEN, SHORT, LAOD and THRU already have Check marks.
On the left hand side it shows SLOT in RED.
I do not understand how come there are check marks on all 4 while I have not yet started calibrations
and no "Standards" connected with the Nano VNA.

*-Connected "OPEN" standard* on Ch0, then pressed Open. Take few seconds, Gray colour become dark Gray colour and then return to normal Gray colour. ( Remember the check mark is already there. SOLT displaying in Red on the Left hand side.

- *T* *hen connected "LOAD" standard* on Ch0 , pressed LOAD. Take few seconds, Gray colour become dark Gray colour and then return to normal Gray colour. ( Remember the check mark is already there. SOLT displaying in Red on the Left hand side.

- *Then connected "SHORT" standard* on Ch0 , pressed SHORT. Take few seconds, Gray colour become dark Gray colour and then return to normal Gray colour. ( Remember the check mark is already there. SOLT displaying in Red on the Left hand side.

- *Then connected one connector of the Blue SMA connector to Port 0 and the other connector of the Blue cable to Port 1 , pressed Thru*. Take few seconds, Gray colour become dark Gray colour and then return to normal Gray colour. ( Remember the check mark is already there. SOLT displaying in Red on the Left hand side.

-Dis connected the cables.

-SOLT now showing in GREEN (all the Graph going crazy in Smith Chart).

- *Save* > SAVE 0

Back > Back > Touch on the screen, to disappear the main menu.

-Connected " *OPEN* " Standard.
*** Pic-002 showing dot on the Right side. Lot of graphs moving.

-Connected " *LOAD* " Standard.
*** Pic-003 showing dot in the middle with more then one graphs.

-Connected " *SHORT* " Standard.
*** Pic-004 showing dot in the left with more then one  graphs.

/////Disconnected the "Standard".

-Back

- *Format* : SWR

Connected Diamond HT antenna "SRH230" (Tri band Antenna 144/220/440 MHz)
***Pic-012 (see the picture in my posting dated Mar 7, 2022)

So I see no difference between the tests I ran on Mar 7, 2022 with firmware version 20210530-412578c and the new firmware ver. 20211227 dated 27 Dec 2021.

Sohail VE3ITU

I had the same problem. I bought my nanoVNA 4Plus in February 2022  and found that only the experimental firmware of 20220301 works. All older firmware did not work.

Hi Michael,

I further updated to the new firmware from 20211227 dated 27 Dec 2021 to 20220301, Build time : Mar 4 2022 - 17:59:21. I still have the same issue. Please see my notes below. any idea what's going on. After your feedback or any other experience member's suggestions if the issue still remain, then I have not choice to contact seller.
Pic 001. Pic 002, Pic 003

- Calibrate > Reset Cal
- Calibrate > Reset Cal +View   ( This is new option in new firmware 20220301, the one as an experiment as of Fri Mar 25, 2022 )

Pic 004

- Back

- Dis play > Channel: selected Ch0 Reflect (Already selected, has check mark)

- Back
- Format : Smith  (one dote appearing on the extreme Right hand side. No calibration standard attached with any port ).

- Tap on the screen > Back

- Display > Trace > Left  Trace 0 as ON (has a check mark).
Trace 1,2 and 3 are turned OFF and grayed out by clicking twice on each.

- Calibrate > Calibrate

Connected first the " *OPEN* " standard on Ch0, then pressed Open. Had a check mark and show on the left hand side "O" in RED colour.
Then connected " *SHORT* " standard on Ch0, pressed SHORT. Had a check mark and show on the left hand side "S" in RED colour.
Then connected " *LOAD* " standard on Ch0 , pressed LOAD. Had a check mark and show on the left hand side "L" in RED colour.
Then connected *2* *Blue coax cable using SMA to SMA connector from Ch0 to Ch1* , pressed *THRU*. Had a check mark and show on the left hand side "T" in RED colour.

Press *Done* : Showing *SOLTE* in Green colour.
Press *Save 1*
-Dis connected the cables.
Press Done.

- *SOLT* now showing in GREEN (all the Graph going crazy in Smith Chart).

- Save > SAVE 1

Back > Back > Touch on the screen, to disappear the main menu.

-Connected " OPEN " Standard.
Pic 005 showing dot on the Right side. Lot of graphs moving.

-Connected " SHORT " Standard.
Pic 006 showing dot in the left with more then one  graphs.
-Connected " LOAD " Standard.
Pic 007 showing dot in the middle with more then one graphs.

So I see no difference between the tests I ran on Mar 7, 2022 with firmware version 20210530-412578c , on Mar 21, 2022 the new firmware ver. 20211227 dated 27 Dec 2021 and now (on Mar 25, 2022) the Experimental Firmware 20220301, Build time : Mar 4 2022 - 17:59:21.

Anyone has any idea what I am doing wrong or this device has an issue.

Thank you,
Sohail VE3ITU.

I think E means Experiment.

Sohail ve3itu

Hi folks,
I contacted the manufacturer,  the Hcxqgroup and the asked me to run the tests and share the pictures,  same what I shared here in this message thread.

They told me the device is defective. Sending me a replacement.

Thank you for those who responded here and helped me, specially Michael.

Sohail ve3itu

Glad to help and that the manufacturer is replacing it for you.

Hi Folks,

Good news to share. I received my replacement a brand new Nano VNA2 Plus 4 in two weeks. Calibration for all the standards for different frequencies are perfect like Michael Brun said in one of the above messages. It should be clear dot on the *Open* , *Load* and *Short* on Smith chart. I will soon post some pictures just to compare the bad one with the good one.

Sohail ve3itu