Re: T-Check for my nanoVNA - Results look excellent below 150 MHz and acceptable up to 300 MHz
On Sat, Nov 9, 2019 at 12:14 AM, Kurt Poulsen wrote: If you got a SMA male male adaptor try to S11 calibrate at the end of the male
male adaptor and either use my female calibration data and remember to subtract
the female famale delay when calibration the S21.
Hello Kurt, Thank you very much for your valuable hints. I made what you reccomendet: 1. Connect the Tee direct to CH0: T-Check_RG316-25cm_CH0-6dB_DSC08176.jpg 2. Add an 6 dB attenuator after the Tee. 3. Shorten the coax cable to RG316 25 cm. 4. Tuned the calibration in NanoVNA-Saver. 5. Adjusted the .S2P file S12 for the 6 dB attenuation. 5. So, up to 450 MHz it is within the 5% Limits. T-Check_Short_CH0-6dB.png Now I know the direction to work on, if neccessary. It is always nice to know your limits :-) 73, Rudi DL5FA
|
Re: T-Check for my nanoVNA - Results look excellent below 150 MHz and acceptable up to 300 MHz
Hi Rudy It is only going to 490MHz and he might use shorter testcable with better performance. If you got a SMA male male adaptor try to S11 calibrate at the end of the male male adaptor and ether use my female calibration data and remember to subtract the female famale delay when calibration the S21. Alternatively do a S11 calibration using the male calibration data (so to speak ideal) and do not subtract the female female delay but instead enable an electrical delay equal to the female female delay. Then you will se improvement but never the right figure. I have forgotten to mention if you use the supplied female female adaptor it has a high loss and that also provided poorer result than a low loss female female. Besides that if you in the spread sheet subtract 1 from the T-Check then you have the "percentage" result right away as 0.1/div = 10%. A good T-Check is never beyond 5% and for the frequency range up to 500MHz for a VNWA it holds in most cases 1-2%. The T adaptor may also be an element of poorer T-Check, a good quality T-Adaptor is mandatory but not so important as long the 10/12 term error correction is not applied, Sorry to disappoint you. Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] < [email protected]> P? vegne af reuterr@... Sendt: 8. november 2019 20:05 Til: [email protected]Emne: Re: [nanovna-users] T-Check for my nanoVNA - Results look excellent below 150 MHz and acceptable up to 300 MHz Hello Kurt, Thank you very much for your enlightening words. I thought it was easier to achieve. What only wonders me, how about the T-Check of Erik, that looks good, how does that come? See T-Check_Erik.png 73, Rudi DL5FA
|
Re: UI Suggestion: Big Numeric Display Format for CW Stimulus Mode
Thank You DL9CAT for implementing the larger font and "big info screen" in your fork of the 4-trace firmware!
I have installed your 0.4.0-1 and is working well.
73, --KV5R
|
Re: Looking for firmware with battery indicator, 1500 and big font
KV5R,Can you do a small test on that version?
Using the touch input, go to config, then version then touch to exit version.
Do that a few times and go into other menus in between.
Now, try to use the jog switch - press enter then tell me if you see the on-screen buttons selected (turn green) as you push the jog switch left or right.
I found that after a few version screens selected by way of the touchscreen, you can no longer see menu changes using the jog switch.
I just want to see if anyone else sees that. It's in hugen's code base, not reald's code.
Thanks,Larry
toggle quoted message
Show quoted text
On Friday, November 8, 2019, 3:47:26 p.m. GMT-5, KV5R <kv5r@...> wrote:
I just installed "reald-0.4.0-1 with bigger font and info screen" and it works fine.
Did 2 cals: 50k-900M and 50k-1500M with no problems (900-1500 range is a little squiggly, as expected).
I used Reset on the nano and did not need to clearconfig 1234. But YMMV.
I was using hugen-AA before and it's also fine. Changed to reald for the "info screen" feature.
All it needs now is batt cal feature.
Note Windows users: reald doesn't put up a dfu on his github; you'll need to use Defuse File to to convert the hex into a dfu, then use Defuse-Demo to load it into the nano as usual.
73, --KV5R
|
Re: Looking for firmware with battery indicator, 1500 and big font
I just installed "reald-0.4.0-1 with bigger font and info screen" and it works fine.
Did 2 cals: 50k-900M and 50k-1500M with no problems (900-1500 range is a little squiggly, as expected).
I used Reset on the nano and did not need to clearconfig 1234. But YMMV.
I was using hugen-AA before and it's also fine. Changed to reald for the "info screen" feature.
All it needs now is batt cal feature.
Note Windows users: reald doesn't put up a dfu on his github; you'll need to use Defuse File to to convert the hex into a dfu, then use Defuse-Demo to load it into the nano as usual.
73, --KV5R
|
Re: T-Check for my nanoVNA - Results look excellent below 150 MHz and acceptable up to 300 MHz
Hello Kurt,
Thank you very much for your enlightening words.
I thought it was easier to achieve.
What only wonders me, how about the T-Check of Erik,
that looks good, how does that come?
See T-Check_Erik.png
73, Rudi DL5FA
|
Re: Short-Open-Load - expected reflected power
I too initially questioned the quality of the RF Bridge, primarily due to the price. A transverters-store clone from eBay seller seller25812 was substantially defective: * one of each 100 Ohm pair was disconnected at the balun end * center conductor of the balun reference coax was shorted to shield at both ends * labels for DUT and REF are reversed, relative to schematic for Ukraine version It works OK after correcting...
|
Re: NanoVNA newbie having problems with new unit
Larry,
Thanks for the suggestion. AID64 on the my Chromebook also shows "No USB devices found." with the NanoVNA connected. Oristo thinks android emulation for some USB devices is a work in progress on current Chromebooks. The WebApp works so the hardware interface between the Chromebook and NanoVNA is functional.
- Herb
|
Re: T-Check for my nanoVNA - Results look excellent below 150 MHz and acceptable up to 300 MHz
Hi Rudy Your problem is that you are not aware how a T-Check is processed. The oscillations you see is because your S11 calibration is done with the reference impedance 50ohm and when you the insert the T adaptor then you measure 25 ohm thru the test cable connected to Ch0 and that is causing impedance transformation. Besides that the output of the T- Adaptor connected to the Ch1 via the test cable is not 50ohm but the input impedance of Ch1 not 50 ohm and this input impedance is not transferred via the Ch1 test cable directly but also subject to impedance transformation thru the Ch1 test cable. All in all a oscillation based on the sum of all these factors. In a real VNA like the VNWA the T-Check measurement is done for a complete calibration of S11, S21, S12 and S22 via a test set and the build in 12/10 term error correction take place. The VNWA software does the figure out the output impedance og the TX port which can be monitored via a custom trace as SS and the input impedance of the RX Port seen via a custom trace called SL. The condition for a T-Check is simply the imperfections of the TX output and RX input is compensated as the were idealy 50 ohm. There is a trick in the VNWA software the a full 12/10 term error correction can be performed by pressing the F2 key on the keyboard as then the t_Check adaptor is sweep in both forward and reverse direction and thus doing a full 12/10 term error correction. By a normal forward or reverse measurement only 6/5 term error correction applied. THE NanoVNA HAVE NO ERROR CORRECTION so you cannot do a T-Check the correct way Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] < [email protected]> P? vegne af reuterr@... Sendt: 8. november 2019 16:28 Til: [email protected]Emne: Re: [nanovna-users] T-Check for my nanoVNA - Results look excellent below 150 MHz and acceptable up to 300 MHz I need help from an expert. My T-Check setup is now 2 x 50 cm RG402 coax cable and a SMA Tee with a 50 Ohm Load, see picture NanoVNA_T-Check_SMA-Tee_RG402_DSC08175.jpg The result, calculated with the spreadsheet from QRP is shown in NanoVNA_T-CheckR-RG402.png The S21 gain shows a big oscillation, see NanoVNA_T-Check-T_RG402-50cm.png If I remove the CH1 coax cable from the SMA Tee S11 looks like: NanoVNA_50-Ohm-Load_RG402.png So, I think the calibration was OK. The attached file NanoVNA_T-Check-T_RG402.S2P can be imported in VNWA, see VNWA_T-Check-T_RG402.png How does that come? What I am doing wrong? 73, Rudi DL5FA
|
Rune,
If I calibrate via NanoVNA-Saver can I save it to the NanoVNA so that I can use the NanoVNA as a standalone device?
Mike N2MS
toggle quoted message
Show quoted text
On November 8, 2019 at 3:25 AM Rune Broberg <mihtjel@...> wrote:
Hello Ulrich,
the NanoVNA-Saver application calibration is in addition to a calibration
done on the device. You should always use the *same* calibration on the
NanoVNA itself when using NanoVNA-Saver's application calibration.
|
Re: NanoVNA newbie having problems with new unit
Herb,
I have no issues with the latest APK on my LG tablet (Android 7) or Chinese cellphone (Android 8.1).
Install the following USB utility and check to see if your Android device detects the nano:
Plug in your Nano and check the peripheral section. It should show everything connected.
Regards,??
Larry
toggle quoted message
Show quoted text
On Friday, November 8, 2019, 10:18:05 a.m. GMT-5, hwalker <herbwalker2476@...> wrote:
Thanks for the tip!? Unfortunately the off-line APK version still does not recognize the NanoVNA.? At least the on-line version allows Chromebooks with the latest OS to attach to the NanoVNA.
Samsung XE500C13 Chromebook 13
- Herb
|
Re: NanoVNA newbie having problems with new unit
Unfortunately the off-line APK version still does not recognize the NanoVNA. Experimenting with other Android apps using USB OTG, the problem appears to be ChromeBook Android emulation, perhaps simply USB dev path naming or permissions. No blame to cho45
|
You're right as far as I can tell - when you want to read data within the
previously calibrated span, you don't need to calibrate again, as long as
your setup is otherwise the same. For that very reason, I usually keep a
50kHz - 1500MHz calibration in C0 on my device.
Having the calibration purely within NanoVNA-Saver is certainly doable, and
something I could implement in the future, with the right support from the
firmware developers of course. :-)
But like others have mentioned: There is a difference between trying to get
the NanoVNA to the level of a high-level VNA, or trying to make it easier
to use for the use cases where the performance is already adequate. For
now, I'm working on some features for the latter, most notably mouse-based
zoom on the charts and logarithmic Y-axis scaling - but also some of the
former, like dialling in port extension in picoseconds within the software.
--
Rune / 5Q5R
toggle quoted message
Show quoted text
On Fri, 8 Nov 2019 at 16:18, Nick <g3vnc@...> wrote: Thanks Rune. I did not understand the relationship between device cals
and nvna-s cals.
Please allow me to check my understanding.
Let's say I want to measure a ferrite choke from 1 to 50MHz. I set up the
cables and do a device cal over that frequency range using an appropriate
cal kit. I save that cal to say C0.
With C0 selected on the device, I repeat the cal on nvna-s using the same
frequency range, same cables, same cal kit and save it to cal_0.cal.
I can then measure my choke over the same frequency range using nvna-s
with as many data points as I like using multiple segments.
Let's say I then want to measure a UHF filter over the range 100MHz to
900MHz. Obviously I cannot use C0 and cal_0.cal. So I set up with
different cables and a different cal kit. I do a device cal over that
frequency range and save it to C1.
With C1 selected on the device, I repeat the cal on nvna-s using the same
frequency range, same cables, same cal kit and save it to cal_1.cal..
I can then measure my filter over the same frequency range using nvna-s
with as many data points as I like using multiple segments and save the
results to s*p files.
What if I then want to measure the filter over a restricted frequency
range, say 400 to 500MHz?
Or a VHF filter with the same the cables and connectors from 100MHz to
200MHz?
Do I need a new pair of cals in either of these cases? (I would say not.)
Is it possible for nvna-s to detect what cal the device is set to i.e. C0
through C4, tell the user and set the correct scan range?
If nvna-s could read raw data from an uncalibrated nvna would that mean
that all cals for fixed bench work could be performed by, and saved in,
nvna-s if the user so wished?
Obviously for portable use the device cals are the only ones available.
On Fri, Nov 8, 2019 at 11:46 AM, Rune Broberg wrote:
by same I mean the *same*. The NanoVNA-Saver calibration is *not*
independent of the device calibration - on the contrary, it is in fact
dependent on that calibration staying the same.
The values returned by the NanoVNA to NanoVNA-Saver are the adjusted values
from the device calibration. NanoVNA-Saver further offers a calibration
based on these values - but it does not know the original raw values from
the device. I guess that could be implemented, but it is not currently.
|
Re: T-Check for my nanoVNA - Results look excellent below 150 MHz and acceptable up to 300 MHz
I need help from an expert.
My T-Check setup is now 2 x 50 cm RG402 coax cable and a SMA Tee with a 50 Ohm Load,
see picture NanoVNA_T-Check_SMA-Tee_RG402_DSC08175.jpg
The result, calculated with the spreadsheet from QRP is shown in
NanoVNA_T-CheckR-RG402.png
The S21 gain shows a big oscillation, see
NanoVNA_T-Check-T_RG402-50cm.png
If I remove the CH1 coax cable from the SMA Tee S11 looks like:
NanoVNA_50-Ohm-Load_RG402.png
So, I think the calibration was OK.
The attached file NanoVNA_T-Check-T_RG402.S2P can be
imported in VNWA, see VNWA_T-Check-T_RG402.png
How does that come?
What I am doing wrong?
73, Rudi DL5FA
|
Thanks Rune. I did not understand the relationship between device cals and nvna-s cals.
Please allow me to check my understanding.
Let's say I want to measure a ferrite choke from 1 to 50MHz. I set up the cables and do a device cal over that frequency range using an appropriate cal kit. I save that cal to say C0.
With C0 selected on the device, I repeat the cal on nvna-s using the same frequency range, same cables, same cal kit and save it to cal_0.cal.
I can then measure my choke over the same frequency range using nvna-s with as many data points as I like using multiple segments.
Let's say I then want to measure a UHF filter over the range 100MHz to 900MHz. Obviously I cannot use C0 and cal_0.cal. So I set up with different cables and a different cal kit. I do a device cal over that frequency range and save it to C1.
With C1 selected on the device, I repeat the cal on nvna-s using the same frequency range, same cables, same cal kit and save it to cal_1.cal..
I can then measure my filter over the same frequency range using nvna-s with as many data points as I like using multiple segments and save the results to s*p files.
What if I then want to measure the filter over a restricted frequency range, say 400 to 500MHz?
Or a VHF filter with the same the cables and connectors from 100MHz to 200MHz?
Do I need a new pair of cals in either of these cases? (I would say not.)
Is it possible for nvna-s to detect what cal the device is set to i.e. C0 through C4, tell the user and set the correct scan range?
If nvna-s could read raw data from an uncalibrated nvna would that mean that all cals for fixed bench work could be performed by, and saved in, nvna-s if the user so wished?
Obviously for portable use the device cals are the only ones available.
toggle quoted message
Show quoted text
On Fri, Nov 8, 2019 at 11:46 AM, Rune Broberg wrote: by same I mean the *same*. The NanoVNA-Saver calibration is *not*
independent of the device calibration - on the contrary, it is in fact
dependent on that calibration staying the same.
The values returned by the NanoVNA to NanoVNA-Saver are the adjusted values
from the device calibration. NanoVNA-Saver further offers a calibration
based on these values - but it does not know the original raw values from
the device. I guess that could be implemented, but it is not currently.
|
Re: NanoVNA newbie having problems with new unit
Thanks for the tip! Unfortunately the off-line APK version still does not recognize the NanoVNA. At least the on-line version allows Chromebooks with the latest OS to attach to the NanoVNA.
Samsung XE500C13 Chromebook 13
- Herb
|
Re: NanoVNA newbie having problems with new unit
NanoVNA Web client After most recent Chromebook updates, NanoVNA Web client now works with Acer CB5-571 Chromebook 15.
|
Re: how to see what firmware version?
Bob,
If your on-screen menu does not have a Version key, then you are running something less than 0.3.0 and you will need to use the console commands to find out how what version you're at.
Check the Wiki on how to access the console commands and how to connect the Nano to your PC via a USB connection.
...Larry
toggle quoted message
Show quoted text
On Friday, November 8, 2019, 8:58:13 a.m. GMT-5, bob <w9zv@...> wrote:
apologies if this has been answered before...? i scrolled thru many pages and didnt see it.
i would like to find out what firmware version my nanovna is currently running, in order to consider if an update is needed.
how can i find out what version of firmware is currently installed?
amazing and useful little device.? it becomes hard to imagine folks complaining about it for $50 or < $200 even, when only a few years ago you needed $10's of thousands of dollars invested in HP or similar to do much the same.? Get some perspective.
-bob
|
how to see what firmware version?
apologies if this has been answered before... i scrolled thru many pages and didnt see it.
i would like to find out what firmware version my nanovna is currently running, in order to consider if an update is needed.
how can i find out what version of firmware is currently installed?
amazing and useful little device. it becomes hard to imagine folks complaining about it for $50 or < $200 even, when only a few years ago you needed $10's of thousands of dollars invested in HP or similar to do much the same. Get some perspective.
-bob
|
Excellent work and document, Herman.
Thanks for sharing.
...Larry
toggle quoted message
Show quoted text
On Friday, November 8, 2019, 7:02:54 a.m. GMT-5, Herman De Dauw <on1bes@...> wrote:
Recently I have replaced my 2.8" LCD with a 3.5" version. Document is in the Files section.
'73 on1bes
|
Kurt Poulsen
Oristo
