开云体育

On Thu, Oct 31, 2019 at 01:50 AM, Alex OE3JTB wrote:

Tried to install on my Droid running v6x, and the Play page says that it is not compatible. This may be because it doesn't work on v6x, or maybe the authors have not configured the page correctly?
Any suggestions, besides rooting my device?

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On the banks of the Piscataqua
Rich NE1EE

On Sun, Nov 3, 2019 at 08:34 AM, <erik@...> wrote:

VNA 1 (nanoVNA) seems at low frequencies to have a Z0 that best matches the
impedance of the cables but shows a substantial deviation above 600MHz

I am new to VNAs, but have wondered during these past few weeks as I experimented with my NanoVNA-H if it is better to calibrate /within/ the 3 bands that use different harmonics.
0-299MHz
301-599MHz
601-900MHz
I suggest this, because I don't know where the Nano switches modes, and staying within the harmonic bands should guarantee that each cal uses a single harmonic. I do all my cals this way, and don't see a penalty, because as a ham, I don't expect to use the same antenna for HF and (example) U/VHF. I think that I need to recal for each geometry anyway, so no point trying to cal to the whole bandwidth.

I see all these traces, and it strikes me that we are looking at a sin(f)*e^(-f)...that is, some sort of sine wave response that decays exponentially. Just a guess...but still wonder what you results would be in each of the 3 Nano harmonic bands.
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On the banks of the Piscataqua
Rich NE1EE

On Sun, Nov 3, 2019 at 04:41 PM, Rune Broberg wrote:

I think maybe the Windows 10 task bar is a few pixels more than the Windows
7 one?

I park my taskbar on the left, because most screens these days have lots more pixels in width than in height, and I auto hide the taskbar.This is especially useful when running several fldigi apps (flmsg, etc.) and onscreen oscope.
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On the banks of the Piscataqua
Rich NE1EE

No. nanovna-saver is written in python, it runs anywhere you can get
python.
I use it on my linux systems.
Shouldn't be hard to add an interval timer to it.

However, I've thought that maybe it would be interesting to make a stripped
down version that is just a panel full of buttons to trigger recording data.

On Mon, Nov 4, 2019 at 07:02 AM, Rich NE1EE wrote:

How about connecting a Pi or summat running *nix and Python.

I like nanovna-saver, but that runs only on Windows? And I don't know that it has an interval timer for data acquisition.
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On the banks of the Piscataqua
Rich NE1EE

On Thu, Oct 24, 2019 at 09:47 AM, Martin wrote:

Is it possible to take a sweep & capture with the standalone Nano VNA then
connect to NanoVNA Saver at a later stage and download the previous sweep
parameters for display ?

How about connecting a Pi or summat running *nix and Python. Not an expert w either one, but have tinkered w the Pi (and others, such as Propeller)

and did a lot of high-altitude (near-space) data acquisition.

So maybe this is a low-cost alternative? Prolly the Pi//Linux/Python (I guess that I should learn Python...sigh) could be running some sort of loop that acquires data at intervals? This is what I did with the Propeller, and the Pi is higher up the food chain.
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On the banks of the Piscataqua
Rich NE1EE

Hi Larry, Erik, Jim,

Thank you very much for your replies, seems what I am after is possible but not as straight forward as I had hoped. Well, need to find the time to experiment a little and see how far I get.

73 Elia,
M0ZHN

I see that I am not the only one who wants to know how to contact developers. I looked on github, but didn't twig to the usefulness of this feature. Oristo replied to another post with this suggestion.

If latest firmware release does not behave as wanted, then add an issue, e.g.,



Thanks to Oristo for this tip to us newbie GitHub users.
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On the banks of the Piscataqua
Rich NE1EE

On Thu, Oct 24, 2019 at 12:35 PM, Oristo wrote:

If latest firmware release does not behave as wanted,
then add an issue, e.g.
( )

Thanks for this tip...I have been wondering how to provide feedback and recommendations to developers.
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On the banks of the Piscataqua
Rich NE1EE

Hi Rune,

Could I also add a request to be able to change the size of the markers on the graphs.

When larger line and plot sizes are used, it can become difficult to see the actual markers.

Thnaks,

Martin - G8JNJ

Thank you Oristo.
I'm not sure how to press pause when the unit is hanging on the antenna up
in the air, that's the reason I think a *scheduled *one scan+pause will do
it.
To clarify my request, let's imagine the following sequence:

1. Prepare the scheduled scan on the NanoVNA (for example set delay 10 min)
2. Connect NanoVNA to the antenna
3. Install the antenna on the working position
4. Wait for the scan+pause to start/finish
5. Bring antenna down and save the data from the NanoVNA via USB

I know there's another solution to this problem: to calibrate NanoVNA with
a piece of cable long enough to reach the antenna in the working position.
However, I think the measurement with NanoVNA connected directly to the
antenna would be more accurate.

Hi Ady

regarding saving the scan and download it later, I think a nice firmware
feature would be to schedule a delayed scan followed by a pause after the
scan.

This is already possible using

This will allow to hang the NanoVNA to the antenna (for example HF multiband
dipole like FD4, or VHF YAGI) and perform a scan without the feeder.
The delayed start of the scan is necessary to allow enough time to install the
antenna in the position.

Not sure why delaying start is necessary; scans until pause are discarded.
Only the final scan before pause is available to upload when USB is reconnected.

G=m/s

The results of this exercise appear to confirm your conclusion in that paper.
I am amazed by how close they agree with those of the full one-port cal and
that of your mini-equation.

That works when short and open results are similar and load signal is small.
Small load signal is generally easy for resistance bridge at low frequencies,
not so much for reflection bridge and higher frequencies.

Open = short works better for nearly no distance from bridge to DUT,
not so well for real cables of some length.

Hi Kurt -

When the calibration kit is loaded in VNWA software
simply open a custom trace and in the Expression line
write s_load or s_open or s_short or s_thrumatch or s_thru
then the trace is shown according for the custom trace
then to save directly as s1p file by a right click on the trace
and use the "Export to s1p file" function.
You must decide on frequency span and number of points in advance

.. and another piece of the puzzle falls into place..
Thanks ever so much!

The very "short" one port equation does get meaningfully close, but diverges with frequency. I haven't computed the impedance deviation yet, so it's too soon to pass judgement. My spreadsheet is getting uncomfortably out of control; and as I am understanding more, it expanded and has become difficult to manage. Before I continue from here, I need to do a refresh/rewrite to get it better organized and to keep it from becoming corrupted. This may take a few days.

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73

Gary, N3GO

thank you,

I made a mistake during calibration, now the reading is good, have a good day

Gilles

Hi Gilles,

I assume you followed a calibration routine as documented. There is one in the file directory. See

/g/nanovna-users/files/NanoVNA%20Calibration%20Considerations%20and%20Procedure_v1.1.pdf

or there are various messages and threads documenting similar approaches. I agree after the cal routine is complete using the standards used in the cal, the thru corrected should read essentially 0 dB.

Alan

hi,
When I am doing a full calibrate O S L iso and thru. I get a -10.8 dB on log mag with the RG174 coax cable. on full RF span exemple: 28 to 30MHz or other frequencies range. channel select is thru...

I don't understand why, I should get around 0dB of attenuation
I have tested a VHF cavity and also a 11 db of attenuation (I should get around 1db att)

any could help

thanks

Gilles

Rune,

While you are at it is there any way to integrate an option so that the
cursor data can be displayed in the appropriate graph display area similar
to the data that you see on the real VNA display. I you need to display all
of the data details you can of course use the display data button but of
course this greatly expands the display area requiring the vertical scroll
bars to be used.

73,
Sam

ARS W3OHM
Owner and Moderator of:
LeCroy Owners Group on Groups.io (Current and Future Group)
LeCroy_Owners_Group on Yahoo! Groups (NOW DEAD Legacy Group)

GIN & PEZ@arg;

New results to please you all the more. I just replaced your mini equation:



with your even smaller equation as presented in Part 3 of your 5 part series as equation (6):

Measurement Uncertainty in Network Analyzers: Differential Error
Analysis of Error Models Part 3: Short One-Port Calibration - Comparison:


Which reduces the equation to a single calibration measurement (Short) only, and reduces the computation to simply:

G=m/s

The results of this exercise appear to confirm your conclusion in that paper. I am amazed by how close they agree with those of the full one-port cal and that of your mini-equation.

I will gather and post more detail on my observations tomorrow.

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73

Gary, N3GO