This message is to help anybody who experienced the same issue as me.

I just updated my SYSJOINT SV4401A VNA with the 0.3.0 firmware posted on the website here: https://www.sysjoint.com/en/content/?145.html

Unfortunately, this 0.3.0 update broke all S21 charts when you calibrate with the new firmware. - It causes some kind of error to be introduced into the CAL file that breaks S21.

Version 0.3.0 does offer better speeds, and UART, so as a workaround, calibrate using the old firmware, update to 0.3.0, and then use your old CAL files.

In my case, my SV4401A VNA was shipped with 0.2.2 firmware, which is not available for download anywhere. Luckily, I saved a copy of my bin file before updating. I want to share it here for anybody else in the same situation who wants to downgrade back to 0.2.2 and didn't take a backup of their bin: https://drive.google.com/file/d/1-NWXV6ROcdTmZXCMCW8ziAkyJ60-vAj6/view?usp=sharing

Just rename it to update.bin, and follow the normal update procedure. I had to repeat it twice to get it to downgrade; it got stuck at 1.5% the first time around, but it worked the 2nd time, thankfully. I have sent an email to SYSJOINT about this issue.

Good Luck!

Dave J

I have two Sysjoint nanoVNA's F-V2s and both are junk. Their quality
control is terrible.

I wouldn't buy anything from them. What a waste of time having to try and
fix their junk.

Hank
On Sun, Dec 11, 2022 at 12:29 AM DaveWJ <davewj100@gmail.com> wrote:

> This message is to help anybody who experienced the same issue as me.
>
> I just updated my SYSJOINT SV4401A VNA with the 0.3.0 firmware posted on
> the website here: https://www.sysjoint.com/en/content/?145.html
>
> Unfortunately, this 0.3.0 update broke all S21 charts when you calibrate
> with the new firmware. - It causes some kind of error to be introduced into
> the CAL file that breaks S21.
>
> Version 0.3.0 does offer better speeds, and UART, so as a workaround,
> calibrate using the old firmware, update to 0.3.0, and then use your old
> CAL files.
>
> In my case, my SV4401A VNA was shipped with 0.2.2 firmware, which is not
> available for download anywhere. Luckily, I saved a copy of my bin file
> before updating. I want to share it here for anybody else in the same
> situation who wants to downgrade back to 0.2.2 and didn't take a backup of
> their bin:
> https://drive.google.com/file/d/1-NWXV6ROcdTmZXCMCW8ziAkyJ60-vAj6/view?usp=sharing
>
> Just rename it to update.bin, and follow the normal update procedure. I
> had to repeat it twice to get it to downgrade; it got stuck at 1.5% the
> first time around, but it worked the 2nd time, thankfully. I have sent an
> email to SYSJOINT about this issue.
>
> Good Luck!
>
> Dave J
>
>
>
>
>

Thanks for sharing your experience.

I also have a SYSJOINT NanoVNA-F V2, but in my case it's been pretty solid, no major issues to report.

There does appear to be an issue with quality control, for sure.

If SYSJOINT open-sourced their firmware, I think their products would be more successful. They would receive bug fixes, QA, and new features completely for free.

The SV4401A larger screen, cap touch, more points, faster CPU, screenshots, etc, really makes it a great platform, and it has so much potential for better software.

I see where you're coming from though, these devices can be hit & miss sometimes. The official Nano sources are a lot more consistent.

Dave

They are not the only ones.  We have been seduced by low prices into buying junk.  This is a natural consequence of dealing with companies with no ethics, no product support, and no long-term thinking.