¿ªÔÆÌåÓý

For your info. There are calibration kits in Ebay where the center pin does not rotate while attaching the connector. Price was about 13€?$

I am using NanoVna saver software and the last action in the calibration dialog is "isolation". How do I do it or how it differs from "open" calibration?

Regards
LM

On Mon, Oct 14, 2019 at 08:39 AM, Jeff Anderson wrote:

Here's a closer look at a screenshot....

...and attached is the missing screenshot...

On Mon, Oct 14, 2019 at 07:40 AM, W5DXP wrote:

Jeff, I'm running edy 0.2.3 and it will display R and X.

Thanks very much, Cecil. I've been too chicken to attempt updating the firmware. Maybe it's time to bite the bullet.

Mel -- edy 0.2.3 is *firmware* that would need to be downloaded onto the NanoVNA platform, itself. I've never attempted it, so I don't know how difficult it is. But take a look at the Wiki section of this group, there are probably instructions.

Also -- you should be able to see X in terms of ohms with NanoVNA-saver. Here's a closer look at a screenshot. You can see that the primary marker readout is in terms of ohms for both R and X, and the plot's 'jX' axis (vertical axis, right-hand side of the top plot) is in terms of ohms.

- Jeff, k6jca

Please be aware both code space and ram are almost full. Any big additional functionality will imply taking out other functionality possibly leading to PC side incompatibility.
Do not dig a private hole but connect on GitHub and submit proposals for improvement with implementation. People like edy555 and hugen are very good at minimizing the footprint of the SW. They may take your ideas and further improve
The collective is much stronger than the individual

The SA612 currently run on 5volt. Max is 8 volt. Will not make a big difference in performance. IIP3 and 1DBC improvement but more noise. Will do some more testing.

Thanks Jeff, near but not quite, It gives the R in terms of ohms, but the X in terms of pF?? Yes I can get there, but it would be nice to see the Mag R in ohms and the X in terms of j like my itger two VNA do.....

--
Mel, K6KBE

Would ¡°uncertainty of errors correction terms¡± not be a better title?

On Mon, 14 Oct 2019 at 15:24, yza <yzaVNA@...> wrote:

#45 : errors instead of "errors" : [NanoVNA] Indications for
"standard" Nominal Values

Hello,

Allow us, please, to demonstrate the big difference between
Indications and Nominal Values for [AnyVNA], using our
[NanoVNA] and our "standard" load [ref2007box], measured
by our [VNA] and thus having the BLUE Nominal Values against
the RED Indications, taken with our [Nanovna], in the following
two figures - in terms of frequency:

"Amplitude" of Rho (in "non-dB" pure numbers) :


"Phase" of Rho (in degrees) :


After that, allow us, please, to rhetorically ask :

"Is there an observer who would like to not call "errors", but just
errors without quotes, these really big differences ?"

Sincerely,

gin&pez&arg

45#



--

Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

Please explain edy 0.2.3 SW Thanks

Mel, K6KBE

Jeff Anderson wrote: I just took a look at my NanoVNA ... and I don't see any way to display R and X.

Jeff, I'm running edy 0.2.3 and it will display R and X.

At 200 MHz it appears to be 55 dB (see attached picture).

#45 : errors instead of "errors" : [NanoVNA] Indications for
"standard" Nominal Values

Hello,

Allow us, please, to demonstrate the big difference between
Indications and Nominal Values for [AnyVNA], using our
[NanoVNA] and our "standard" load [ref2007box], measured
by our [VNA] and thus having the BLUE Nominal Values against
the RED Indications, taken with our [Nanovna], in the following
two figures - in terms of frequency:

"Amplitude" of Rho (in "non-dB" pure numbers) :


"Phase" of Rho (in degrees) :


After that, allow us, please, to rhetorically ask :

"Is there an observer who would like to not call "errors", but just
errors without quotes, these really big differences ?"

Sincerely,

gin&pez&arg

45#

On Mon, Oct 14, 2019 at 03:14 AM, hwalker wrote:

You can also get the phase by taking the arctan (im/re). "
--John Gord

Herb,

John Gord is on the right track about the phase. To be a bit more specific, the phase angle from -180 to 180 degrees in Excel is converted using atan2(im,re) which is the four quadrant arc tangent. The result from atan2() in Excel is in radians and you must convert to degrees if that is what you want. For example, to get the phase angle in degrees from S11 in row 5 once you load the S2p file into Excel you will need to put the equation "=atan2(c5,b5)*180/pi()" in a cell, say column 11 or something like that.

Have fun.

--
Bryan, WA5VAH

Erik, photos at msg 4295.
A local regulator is used, adjacent to the mixer.

Maybe a separate, local regulator could be used at each mixer to decouple them from the common supply?

Awaiting your tests...?

Regards
Larry

On Mon, 14 Oct 2019 at 04:49, Dr. David Kirkby from Kirkby Microwave
Ltd <drkirkby@...> wrote:

There are some features that I would like added to the firmware connected
with calibration. I don¡¯t mind making them public, but are quite happy to
just add them for my own use.

Are there any guidelines around for what one should and should not do? Some
examples of adding menus? Constraints etc?

I believe that the firmware is written in Python.

I hesitate to /instruct/ anyone on firmware, but I have some thoughts to share.
tl;dr There is a minimum set of skills that should be in place before
modifying the firmware, even for one's self alone.


If one is contemplating getting started in firmware mods, one might
consider the following:
1) Download the firmware source code
2) Set up the compiler environment
3) Make the most trivial change possible: set the board/version text
and compile the firmware
4) Flash the changed firmware and test it

Once comfortable with this skill set, one might progress to understand how:
5) The firmware interacts with ChibiOS
6) The firmware interacts with the hardware
7) The firmware implements VNA algorithms
8) To return/donate code to Github

If all this sounds... unappealing, I would counsel that one should
make a formal feature request on Tomohiro's Github.

--buck

Hi Mel, good to see you (and your Bauer) on the group.

I just took a look at my NanoVNA (which I've had for a month or two, so it doesn't have the latest firmware), and I don't see any way to display R and X. In fact, I only see R and X as marker annotation when displaying the Smith Chart (and in this case X is not in terms of ohms, but apparently H or F).

But if you don't mind using your NanoVNA with a PC, check out the NanoVNA-Saver application, which runs under windows. (You can download the .EXE file from this page: )

I've attached a screenshot showing a plot of S11 in terms of R and X (it's the top plot of the two). Is this what you are looking for?

Best regards,

- Jeff, k6jca

P.S. It's a very cute little tool. I've added N connectors to mine. Tell Ray 'VAB he should get one, too.

Erik,The Japanese Ham on twitter (I put photos in the files section) was running CH0 from an ext supply per the top photo. What would happen if you raised the supply voltage? It can take 8v max.?The spec sheet shows a VCC filter using a 5.5uH and a couple of caps.?
Also, that ip5303 is probably putting out a pile of radiated RF noise not only on the supply lines. Try running the device on 4 AA batteries for your next test. I don't know off hand what the max Vin for the 3v Reg is though.?
Larry



On Mon, 14 Oct 2019 at 3:04 AM, erik@...<erik@...> wrote: Changed the offset from 5kHz to 12kHz and running the nanoVNA? directly from a linear 5V power supply. Even with USB connected the latter makes a substantial difference in noise levels
Guess adding some inductors to the nanoVNA to block VHF/UHF supply noise is the next step

Those 2 resistors are only required if you are using a usbc to usbc cable on a usbc computer port as they tell the computer the type of device being connected. If you're using a usb3 to usbc cable on a normal usb3 or 2 port, they don't matter.

On Mon, 14 Oct 2019 at 1:33 AM, Starsekr via Groups.Io<Starsekr@...> wrote: Jacon, if the resistors are missing, what does that do to USB communication? Are they just for using the USB as a sink (load?) for charging a battery through the USB port? Without them does the upstream usb just see the Nano as a low power sink?

I had uploaded a zipped file in the Forum's file section that has info on the matching pad, if you would care to look at.?



On Mon, 14 Oct 2019 at 12:14 AM, Starsekr via Groups.Io<Starsekr@...> wrote: I started this topic because the original thread? got hi-jacked to antennas matching.? :-(
H Walker posted? in Msg #4702
/DMR,
/Thanks for your contribution.? A previous DFU file was uploaded for making 75 ohm system measurements
/ ("50-75 Ohm_Use transformer-10.10.2019.ra").
/The uploader made special note that in order for measurements to be accurate 50-75 ohm matching pads were required on CH0 and CH1.? Does your
/mod also require matching pads/transformers, or are you applying some type of mathematical correction factor?
/
/- Herb

** Herb,? I can't find that file.? Could you give us a message number?? Have you opened it?? ? Thanks? Jim

Dr. David Kirkby posted in msg. #4540
/1) Minimum loss pads can be used to allow calibration with 75 ohm
/calibration kits. There are 75 ohm versions of both N and BNC connectors,
/and calibration kits for both available

**David, I understand the 7 db loss pads..? Would wide band transformers work also?? Coilcraft makes several, one set is sold on Mr. Kurt Poulson's? SDR-Kit site and on eBay, or maybe we could roll our own , at least for 3-30 Mhz or 6, 4 or 2 meter bands.? One pad/transformer for each VNA port used?

* Anyone.? Assuming? I understand me using pads/transformers, and calibrating at the desired impedance (75 ohms) at the test fixture, then the NanoVNA Smith chart, while showing 50 ohms is actually 75 ohms reference, and the graphs will be ref. to 50 ohms, what math operation do I do to get a 75 ohm graph and (maybe using Excel) to get 75 ohm values?? URLs or pointers to web sites are welcome.

thanks,
Jim, KA6TPR

Hi Herb
The s1p and s2p files are plain txt files so you can open then directly from Excel, choosing a separator then you can save tocsv. However the first 4 lines are text telling what type of data are in the columns which you may removed.
I use also a plane txt editor like notepad+ to remove sections of the frequency range e.g. from 500MHz upwards and the like
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af hwalker
Sendt: 14. oktober 2019 04:06
Til: [email protected]
Emne: [nanovna-users] Save S21 data in CSV format

I have some S21 data (see attachment) that I want import into Excel as either tab or comma delimited frequency data pair. Neither nanovna-saver or nanoVNASharp support exporting to a CSV file. Has anyone written a python script that will get the NanoVNA S21 data and save it in CSV format? I suppose I could use nanovna-saver or nanoVNASharp to save to a s2p file and then parse that file to CSV, but I don't have the programming skills or understanding of the s2p format to do so. Any help would be appreciated.

Regards,

-Herb