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Hi

The way I see the "marker points" is semi-automatic. The user will have to press e.g. the LPF button, if the DUT is a LPF. The S/W then looks from low to high frequency for the selected "marker points". They may be way off if viewing a filter in the stop band. It is at the user's discretion to understand the functionality. Otherwise the user can place the markers manually. I don't expect any AI in this matter.

Bo

So it is already thin.? No help there...
Mike WY6K


"... somewhere in the distance, there's a tower and a light, broadcastin' the resistance, through the rain and through the night..."

On Fri, 27 Sep 2019 at 20:48, Bo, OZ2M <groups.io@...> wrote:

Hi
One thing is loss, but also isolation is an issue. I have a circuit on FR4
on my desk right now, where the isolation above 1,7 GHz cannot go higher
than around 55 dB. Heavy shielding may help, but shielding and tooling are
cumbersome and expensive.

Bo

How thick is your FR4? Thinner board will keep the RF more concentrated in
the dielectric below the traces.

Dave.
--
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

Oristo,
thank you! Exactly what I need!

Now, to find time to implement all the things I want to do .. oh, and fix
all the bugs... ;-)

--
Rune / 5Q5R

0,8 mm.

Hi Maurizio,
good to hear that the antivirus cleared it - phew!

I don't know if I can do anything to make that go easier, other than put
fewer viruses in? ;-) I guess fewer than none is difficult.

I hope you enjoy using it!
--
Rune / 5Q5R

Screenshot/image saving is definitely interesting! Currently, the
graphs/plots are all painted directly on a Qt widget,
so I would have to find something that could save those.

Does this help?
"Here is the simplest way to save a widget as an image. This approach
works on Qt 5:"
ui->myWidget->grab().save("image.png");

Hi Bryan,
great to hear that the software just runs, and I'm also happy that the
calibration assistant worked out. It was really a last-minute addition, so
I'm happy it works! ;-)

The plot scaling for the dB-based plots needs some work, I agree. User
settable is a good option, but I think I want to make the default scaling
that it attempts to have ~6-8 horizontal "segments" on the screen by
default - and picks a reasonable scale for that. 1dB might be a bit much
for 10dB total span, but maybe 2dB instead? I hear what you're saying on
phase plots, and I'll put user settable scaling in there as well.

Very good to hear that the averaging works! And thank you very much for the
encouragement :-)

--
Rune / 5Q5R

On Fri, 27 Sep 2019 at 18:53, bryburns via Groups.Io <bryburns=
[email protected]> wrote:

Rune,

Thanks for your continued outstanding work! :>).

I am running 0.0.12 on Windows 7. All I am doing is downloading the file,
creating a shortcut to it , and clicking on the shortcut. No issues
observed.

Calibration assistant works fine for me. This is a nice addition. Saving
calibration is important after creating a new calibration.

S21 Marker phase is now the same as the plot and I think both are correct
:>).

I really like the new plot scaling capability because that allows one to
"zoom-in" on features of interest in the data without changing the
frequencies of interest and running another sweep. This is very useful for
careful looks at the information we have available.

I have one suggestion for scaling in a future release: When a max to min
range of 10 dB in amplitude (S11 amplitude dB or S21 amplitude in dB) could
you include 1 dB horizontal lines on the plots? Perhaps an equally useful
solution would be to let the user specify the dB per division for the
y-axis This would help interpretation when looking at things like
pass-band ripple, S21 attenuation of a cable, or .... This idea is
relevant to phase plots as well.

I have been using the averaging capability and think I am reliably
measuring S21 stop-band filter rejection down 50-60 dB from pass-band
attenuation values. The filter I am measuring is a stop-band filter for
the 88 to 108 MHz FM broadcast band here in the US. The averaging does
help in this situation to reduce the noise that is present in the nanoVNA
at those amplitude levels. I see plot-to-plot variations of less than 0.5
dB pk-to-pk. I consider this quite impressive for such an inexpensive
device and free software.

Again, great work on this software. Very helpful!

--
Bryan, WA5VAH

For those on this list first venturing into the v.h.f. and u.h.f. regions
and who would look for repeatable results down around minus
50dBm and quibble over a tenth of a dB, BNC is not the way to go.

FWIW, calibrating 50kHz to 100MHz with these 34cm SMA-to-BNC pigtails:

.. and a generic BNC terminator and female coupler
yields lower CH0 LOGMAG when subsequently remeasured (-68 to -81dB)
than do included SMA cable and terminator (~ - 63dB)

For 500-900MHz
CH0 LOGMAG with BNC pigtail remeasured after cal yields -47 to -51 dB
while remeasuring SMA pigtail after calibration yields -68 to -73 dB

For frequencies of interest >>to me<<, BNC appears better..

Hi Bo,
now I've gotten to your long list of ideas! Thanks for providing them!

Screenshot/image saving is definitely interesting! Currently, the
graphs/plots are all painted directly on a Qt widget, so I would have to
find something that could save those. I think it should be possible, though.

Exporting a general frequency/amplitude (or even amplitude/frequency) file
shouldn't be much of an issue. But, maybe it relates to your next
suggestion: The auto markers for filters. I'd *love* to do that! My biggest
issue is finding a way to 1) identify the filter, 2) find out what the
passband is, and what the passband level/ripple is, and then identify the
3dB/10dB etc. points. The latter part, finding the points, is "easy". What
worries me is the first part :-)

The marker architecture is fully set up to allow for more than 3 markers -
but to fit in 1366x768, it's currently limited to 3. I think I'll add it as
a setting so you can have more. :-)

Thicker trace lines should be an easy setting to make.

The cosmetic points are all sensible, and I'll endeavour to have them
included soon! The only exception is the COM port bit: The current
functionality already finds the correct device if possible, so a dropdown
menu would only really be required if you have more than 1 NanoVNA
connected... I don't think I'll present the users with devices that the
software can't identify as compatible, for now at least, but maybe the
connection functionality needs an overhaul at some point.

Segments: This was previously called sweep count, and is really the base
functionality of the software, the sole reason I wrote it: It refers to how
many segments the sweep span is broken into, each of 101 sample points, in
order to increase resolution over the default the NanoVNA provides. So
putting in 10 provides 1010 points, 50 gives 5050 points, etc. The label
next to it presents the distance between each data point, as that's proven
useful for me, at least. Hz/step is my term for the number of Hz between
two data points .. maybe that's just my own terminology bleeding through, I
don't know. I'm open to suggestions :-)

Thanks again for taking the time to write out all these suggestions!
--
Rune / 5Q5R

Thanks Warren.? Mine has those shields.? I have heard that the shields increase the dynamic range above 300 MHz and especially above 600 MHz.? Is that not true?
Mike WY6K

Bo,?
HOw thick is that FR4 board?? Thinner material would improve the isolation, right?
Mike WY6K

On Fri, Sep 27, 2019 at 10:04 PM, Bo, OZ2M wrote:

Should it be an option, in the S/W, to set the max fundamental frequency? I am
not thinking of the 1,5 GHz possibilities as such.

There is no such option. You can modify firmware but the logic for frequency boundaries is not easy, needs to deal with this.

By the way, edy555 firmware uses different frequency segments boundaries. You can try edy555 firmware, may it will help to solve your issue with no need to change firmware code.

Hi John,
if you experience crashes, please try:
- Running the program for a command prompt, which preserved the crash
message,
- Running using "-D logfile.txt" as a parameter, which saves debug data to
a file, which you can then pass to me for further analysis.

It *may* happen if you have not calibrated the NanoVNA itself, and it sends
values that are so unrealistic, the program doesn't know how to parse it.
Generally, measurements indicating severely positive gain (more than 30dB
maybe?) are rejected as corrupted. If the same measurement shows bad values
more than 20 times in a row, the program stops (and reports an error on the
console). It's not supposed to *crash* when it does this, but ... I think
sometimes it does. :-(

--
Rune / 5Q5R

qrp.ddc,
I purchase cables of unknown quality at hamfests and the nanoVNA has paid for itself in helping me avoid selecting cables that physically looked fine, but from both cable ends looked like virtual shorts using the nanoVNA TDR function. With your access to better equipment, the nanoVNA's TDR function probably does seem like a toy, but if the user realizes its limitations and doesn't expect laboratory quality from a $50 device, the function is still a worthwhile tool and learning feature. If the TDR function tells me that a reel of cable marked 25 meters is 24.5 meters that's close enough for me to feel confident purchasing it. Carrying a laptop with me to do the same TDR measurements is in-convenient, although at home I do use NanoVNA Saver to perform TDR measurements. With the multiple firmware versions that have appeared on the scene, maybe one of the developers will branch off a version that removes the TDR function and implements the features you would rather have. That's the great thing about open source projects, the source code is open to modification however it suits each of our individual needs.

Herb.

did you tried original edy555 firmware?

Firmware from hugen79 and from edy555 have different frequency modes. So they have different behavior at different frequency boundaries.

In my previous post, I was referring to coax from my hamshack to the antenna - not a piece of transmission line a foot or 2 long.
Please remember that from a practical viewpoint, LOW resolution in a handheld device is much better that NO resolution (ie: no TDR function).

...Larry

Hi

From a market volume point of view it might be an idea to divide the RF boards into:
1) Si5351A, as now. This is more than fine for the vast majority of radio amateurs
2) Si5351A + ADF4351, lower volume. Covers my frequencies of interest
3) Si5351A + e.g. ADF5355, very low volume and very high cost

They may all share the same digital processor and display boards. Could the digital processor board be a RPi? If so, then this may have a huge impact on the price, and there is a much higher volume to drive the development of this platform. It might be a bit more clunky though.

One thing is loss, but also isolation is an issue. I have a circuit on FR4 on my desk right now, where the isolation above 1,7 GHz cannot go higher than around 55 dB. Heavy shielding may help, but shielding and tooling are cumbersome and expensive.

Bo

Don't sell yourself short, Frank: we hams can sometimes contribute

on this list.

It's a fuzzy faced young engineer or academic who remains confident

that he has nothing to learn from a genuine ham of long and diverse
experience. Not all of us are simply warmed over chicken banders. Some
of us have ended up embarrassing engineers.

Please continue to contribute.

John

at radio station VE7AOV.

On 2019-09-27 5:00 a.m., Frank Dinger , EI7KS wrote:

Yes ,indeed a 5V USB powerpack ,readily available ,even from supermarkets , will do fine.

For those needing a Li-Ion cell (nominally 3.7V) , I get these from discarded Laptop battery packs . These packs are discarded because usually only 1 of the 6 cells is no longer OK.
I take these packs to bits and charge each cell individually with an appropriate charger (usually good for charging 4 cells at the time) I then fit cells in 18650 cell holders available from Banggood and other on-line retailers.
There are 2 types of cell holders , for 1 cell and 4 cells.

WIth the cell holders I make multiple cell battery packs to feed my Yaesu FT-817 , QRP transceiver
For this transceiver I use 4 multiple cell units in series ,ensuring that the cells will be re-charged when the radio input voltage has dropped to 4*2.8V=11.2V To ensure a long life a Li-Ion cell should not be discharged below 2.8 V
The above just for info.
After all I am just a radio AMATEUR.

Frank , EI7KS

...

--

Tried it on two different Windows 10 machines - it seems some combinations of sweep settings cause the program to close suddenly. This occurred on both PC's.

Calibration was done (400kHz - 5MHz), amateur bands selected to show and sweep was set to 3.5 - 15 MHz.