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From: roncraig1@...
[]
It is possible to tweak the synthesizer frequency setting to account for any TCXO tolerance. I don't think this function is written into the firmware and if it is not it might be something that could be put in future firmware. There would be a calibration register in Flash memory for freq offset and the firmware would calculate the required synthesizer setting offset to the desired freq.
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Whilst the NanoVNA series are not designed as high stability frequency standards, I do agree that having the ability to set a "ppm" value for the master oscillator would be a very useful enhancement.

Copied the suggestion to the NanoVNA-F group.

David GM8ARV
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv

PS. also not sure how accurate you can be with zero beating. There may be a demodulator low freq rolloff issue..

Hi Herb and Rune
The S21 phase delay has been fixed OK and the S21 group delay are still correct, thank you indeed to Rune
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af hwalker
Sendt: 12. januar 2020 00:05
Til: [email protected]
Emne: [nanovna-users] NanoVNA-Saver v0.2.2 #nanovna-saver

Rune has released a "Back From Christmas Update" a few hours ago. See details at: . I'll leave it to Rune to go into any particulars.

- Herb

The nano's have a TCXO module which is not adjustable. The schematic shows a DAC freq trim control line from the uP but I believe all the nano's, beyond perhaps the first ones made, have a TCXO that is not adjustable and their Vcontrol line on the TCXO does not exist. The pad on the TCXO for VC position is just grounded through a zero ohm resistor. You can replace the TCXO with one that does have a Vcontrol but I would not recommend it. The TCXO temp tracking is 0.5 ppm over temp. The initial build tolerance is 1.0 ppm.

The Si5351 has the ability to warp a crystal resonator but since the nano's feeds a clock from the TCXO the warping function will not work.

If you are in fact getting 110 Hz off freq at 10 MHz freq setting you are 11 ppm off freq. This would only be possible if you had a TCXO that did have Vcontrol and it is grounded. You can remove the zero ohm chip resistor to ground on the TCXO Vcontrol pin and put a 0.6v to 3.3vdc variable supply on the pin and see if the freq moves indicating you do have a TCXO with Vcontrol.

The Si5351 has a lot of spurious frequencies and you might be zero beating one of them by mistake.

The nano's should be less then 1 ppm for frequency tolerance.

It is possible to tweak the synthesizer frequency setting to account for any TCXO tolerance. I don't think this function is written into the firmware and if it is not it might be something that could be put in future firmware. There would be a calibration register in Flash memory for freq offset and the firmware would calculate the required synthesizer setting offset to the desired freq.

Thank you so much for the development of the NANO-Saver software. It has
been a blessing in my antenna system work. I do have one request. I
actually like the metric system but many of those that I show the results
have long been English measurement people. In the next iteration of this
software would it be possible to have a choice of metric or English
measurements (Feet vs Meters)? Again, I really appreciate this software and
its functionality.

*Clyde K. Spencer*

Rune,
I'm using firmware 0.4.3Q and the new screen capture module has worked great with all screens I have thrown at it. Thanks for this addition and hope you enjoyed the holidays.

- Herb

On Sun, Jan 12, 2020 at 04:45 AM, Leif M wrote:

I forgot the sign, + is surely not good. Is 1690ps good for a 32cm or one foot of coaxial?
===================================================
For me the easiest way to determine a starting value for cable compensation is to use the TDR function of the NanoVNA (see attachment). It scales the x-values in units of time. The screenshot was taken using the latest version of Rune's excellent NanoVNA-saver application.

- Herb

Interesting. I do not recall having to sudo the previous version. I'm not a programmer, but I'm wondering what changed? The instructions in README.md are the same.

73

-Jim
NU0C

On Sun, 12 Jan 2020 04:36:45 -0800
"Andrew Harmon" <andrew.harmon@...> wrote:

Oh yeah, forgot the sudo step. I knew there was something else I had to do to make this work!
so:
git clone
cd nanovna-saver
sudo python3.7 -m pip install .

I rather like that "stupid switch". All three actions in one place. Handy.

73

-Jim
NU0C

On Sun, 12 Jan 2020 00:05:10 -0800
"hwalker" <herbwalker2476@...> wrote:

On Sat, Jan 11, 2020 at 09:00 PM, DaveH52 wrote:

Did you get rid of that stupid switch?
======================================
Per developer and see attachment:

" - Jog switch sensitivity has been improved.
- Enter DFU (for firmware upgrade) by pressing down the jog switch at power-on. "

So no, the jog wheel switch is still present but usability is supposedly improved. Hopefully that means the switch is now interrupt driven. Looking for some of the first nanoVNA-H4 buyers to post feedback on this subject. I personally haven't experienced any switch related mechanical problems with the nanoVNA-H's that I purchased directly from hugen's Alibaba store (10 for classroom use). I can't comment on the quality of jog switches sourced by other clone manufacturers.

Gabriel Tenna White has said that her coming 3 GHz version of the nanoVNA will use push buttons instead of a multi-function switch. If the multifunction switch really irks you then that will be your best out of the box option.

- Herb

I forgot the sign, + is surely not good. Is 1690ps good for a 32cm or one foot of coaxial?

My answer above means, as you probably know, that you can fine tune the frequency of a crystal by changing capacitors around it.

Jim KC2DHU - Let us know if you got it working. Curious to know what the results are. Thanks

--
Andrew Harmon - KD5RKO

Oh yeah, forgot the sudo step. I knew there was something else I had to do to make this work!
so:
git clone
cd nanovna-saver
sudo python3.7 -m pip install .
--
Andrew Harmon - KD5RKO

Hugen,
I noticed on the new NanoVNA-H4.2 PCB there is an unpopulated silk-screened area labeled "CARD1". Does that imply that a SanDisk card is in the works for a future version of the NanoVNA-H4? Also, with the increase in the flash size, are there any plans to eventually increase the number of measurement points?

- Herb

On Sun, Jan 12, 2020 at 01:00 PM, DaveH52 wrote:

Did you get rid of that stupid switch?
Dave

Multi-function switches still exist. In nanovna-H4, the plastic case can fully protect the multi-function switches, so it is no longer a problem. Unfortunately, our software is still not optimal, and sometimes the button requests cannot be processed normally, even if it is replaced with a button, it does not help. AA6KL is improving the software, and if the community has suggestions about the software, it can be submitted to him.

hugen

On Sat, Jan 11, 2020 at 01:45 PM, Kevin B wrote:
So I just dropped mine and the screen only turns on, nothing is displayed. Does anyone have an actual web link for a replacement?
===================================================================================

The following link was posted by another user who replaced his screen:


For exact replacement, select the touchscreen, 2.8" display. A similar unit may be available on eBay or Amazon.


- Herb

The article is a quick read:



Marco

On Sat, Jan 11, 2020 at 09:00 PM, DaveH52 wrote:

Did you get rid of that stupid switch?
======================================
Per developer and see attachment:

" - Jog switch sensitivity has been improved.
- Enter DFU (for firmware upgrade) by pressing down the jog switch at power-on. "

So no, the jog wheel switch is still present but usability is supposedly improved. Hopefully that means the switch is now interrupt driven. Looking for some of the first nanoVNA-H4 buyers to post feedback on this subject. I personally haven't experienced any switch related mechanical problems with the nanoVNA-H's that I purchased directly from hugen's Alibaba store (10 for classroom use). I can't comment on the quality of jog switches sourced by other clone manufacturers.

Gabriel Tenna White has said that her coming 3 GHz version of the nanoVNA will use push buttons instead of a multi-function switch. If the multifunction switch really irks you then that will be your best out of the box option.

- Herb

Did you get rid of that stupid switch?
Dave

I ran into this error ("python setup.py egg_info" failed with error code 1 in /tmp/pip-build....) also in Kubuntu 18.04. All known dependencies were met and the previous version had installed and ran as expected. The issue seems to be the installer was trying to write to /tmp as an ordinary user, which is not allowed. ~/tmp would have been a better choice, perhaps.

So I ran the install as sudo. It installed and seems to run OK in userspace, although I have not connected my NVNA to it yet. Whatever can of worms I may have opened by doing this I am sure I will find out later....

73

-Jim
NU0C

On Sat, 11 Jan 2020 18:46:07 -0800
post.marcel@... wrote:

Hi Jim,

I had a similar issue on Debian 10 the other day. It seems like components of the Python environment are not automatically kept up to date when simply running apt-get. So after running:

python3.7 -m pip install -U setuptools

... I also ran:

pip3 install --upgrade setuptools wheel pip3

Which then prepared the environment so I could run the nanovna-saver installer.

HTH

Marcel VK2CEL