开云体育

On Wed, 18 Sep 2019 at 22:35, Kurt Poulsen <kurt@...> wrote:

Qrp.dd (whoever you are)
It seem like the distance from center conductor to flat part is as long as
to the top of the female SMA so probable without any influence.
You can test it yourself ....

I don’t know if all the NanoVNAs are being shipped with the same open, but
I tested the open shipped with my NanoVNA using an HP 8753ES VNA after
first calibrating with an HP 85052B cal kit. The open did make a *small*
difference - a bit under 1 degree of phase difference at 900 MHz.

It did however cross my mind later that I had a 3.5 mm test port, rather
than SMA, so it would be worth my while repeating with SMA. My own
experience with both 3.5 mm and *SMA* connectors indicates adding *any*
sort of open ended device on the end, does make a measurable difference to
the phase, but I would have thought it pretty insignificant at 900 MHz.

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

I use this.... It's handy for people like me who understand radio, but find computers a bit of a mystery....

Just wondering if vnaJ software can be used on the Nano ?

Anyone tried it ?

73 de Andy

I thought Windows users just pressed Alt + Print screen key to
grab a screenshot ?

Then open up any graphics editor or Paintbrush thingy and Control V
to paste it into the graphics editor.

No need for any extra software for grabbing the screen.

On Linux it's usually just Print Screen key in its own, then paste to graphics editor, save or edit as desired.

Hope this helps.

73 de Andy

Qrp.dd (whoever you are)
It seem like the distance from center conductor to flat part is as long as to the top of the female SMA so probable without any influence.
You can test it yourself by calibrating using nothing for the open and enable S11 phase trace with a resolution so you have a slanted line dropping down some half the screen at 900MHz. Then mount the open adaptor and see if the trace is changing at all. If a change used the Display/Scale/Electrical delay and adjust until the line is horizontal (50KHz to 500MHz as probably a straight line for that frequency range) and the remove the open adaptor and see the difference by repeating Electrical Delay setting until same trace and the difference between the two Electrical delay setting is the added delay for you open.
Remember to reset the Electrical delay to 0 after the test
-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af qrp.ddc@...
Sendt: 18. september 2019 19:05
Til: [email protected]
Emne: Re: [nanovna-users] Filter measurement

On Wed, Sep 18, 2019 at 04:39 PM, Kurt Poulsen wrote:

It also depend what the NanoVNA user gets delivered or purchase later
on. If it is one with a disk, then throw it away

I got this open load with NanoVNA, is it bad?

On Wed, 18 Sep 2019 at 22:21, Dr. David Kirkby <
drkirkby@...> wrote:

Does anyone have any chassis mount APC7 connectors, similar to in the
attached diagram? The outside must be APC7, but the inside could be APC7,
N, solder mount, or at a push SMA/3.5 mm. Unfortunately, 3.5 mm seems to be
by far the most common, and that's the least desirable. I found somewhere
on the web with what I wanted, which is where I pinched that photograph
from. But they want stupid amounts of money for them.

I'm looking for 4 of them.

FWIW, I intend packaging up a NanoVNA with an APC7 OSL cal kit on the
actual enclosure and having something with known properties. Why carry a
cal kit when you have it built-in? Okay, APC7 must be one of the least
likely connectors to use with a NanoVNA, but I fancy doing it just for the
hell of it.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

Does anyone have any chassis mount APC7 connectors, similar to in the
attached diagram? The outside must be APC7, but the inside could be APC7,
N, solder mount, or at a push SMA/3.5 mm. Unfortunately, 3.5 mm seems to be
by far the most common, and that's the least desirable. I found somewhere
on the web with what I wanted, which is where I pinched that photograph
from. But they want stupid amounts of money for them.

I'm looking for 4 of them.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

Hi Steve,
1366x768 is difficult to fit all the things I want on the screen into -
maybe in a later version, but for now, it's going to be difficult to fit
everything. Each of the graphs/charts is at least 400 pixels tall, and the
window frame etc. is in addition to that.

If you're running Linux (possibly Mac?) you may be hampered by a large
default font size. 0.0.10 allows you to change to a smaller font, which
saves some space.

On Windows, capturing a screenshot can be done using the "snipping tool".
On my PCs, it has come pre-installed.

I'll try to keep the plight of small screen users in mind for the future
releases :-)

--
Rune / 5Q5R

Is it possible to resize the screen so the entire screen will fit onto my computer screen? Currently I have to scroll up and down to see the entire page. Perhaps I need to change the screen resolution on my monitor. My native screen resolution is 1366 x 768.

Is there a way to capture an image of the screen and save as a .jpg file. I see other poster on the group showing screen images but I'm not sure how they are creating the images.

Thanks,
Steve_WB8GRS

On Wed, 18 Sep 2019 at 19:54, <erik@...> wrote:

Ah. Correct. He did not refer to the model structure but used direct
numbers in the code.

That

c = 50e-15;

needs to be replaced by a function

C(f)=C0 e-15 + C1 e-27 f + C2 e-36 f^2 + C3 e-45 f^3

where C is in farads, and f in Hz.

That's the format used by all HP/Agilent cal kits, which are by far the
most common on the market. Copper Mountain use the same, and others use
something similar.

where for a constant 50 fF, it would be

C0=50, C1=C2=C3=0.

The values of all the Keysight cal kits can be found at



Many kits have different values for male and female parts.

The very common 85033D or 85033E (3.5 mm kits) have identical values for
male and female, but the common 85032B N cal kit does not, and neither does
my 85054B N cal kit. Obviously for APC7 kits it is irrelevant.

It would be good if the user could define a few cal kits, and name them.
For example, the kits I have are

* 85050B (APC7)
* 85052B (3.5 mm)
* 85054B (N)
* 85038A (7-16)
* 85039B (F)

None of those kits are going to be common on the use market at a price hams
are likely to be able to afford, although the 85052B does share the same
coefficients as the 85033D and 85033E, which are quite common. The 85050B
(APC7) can often be found cheaply, but it is not a kit most people are
going to want.

I personally intend building cal kits for every connector I can think of
into a box that the NanoVNA fits in. That's partially out of the
practicalities of never have to carry a cal kit, but partly out of the fact
that I can do it.


--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

Hi David,
I haven't considered it closely yet. A quick numerical average would be
obvious for doing just a few sweeps, while a more complex look at the data,
including for example showing some form of error bars, might be useful for
more in-depth analysis. I don't necessarily intend to break new ground
here, and I haven't yet looked at what's the industry norm for averaged
display.

Do you have suggestions?

--
Rune / 5Q5R

On Wed, 18 Sep 2019 at 22:15, Dr. David Kirkby from Kirkby Microwave Ltd <
drkirkby@...> wrote:

On Wed, 18 Sep 2019 at 20:30, Rune Broberg <mihtjel@...> wrote:

Hi Bruce,
good to hear that it works! Averaging is on the roadmap, probably for
0.0.11 (or 0.1.0 or 1.0.0, however I name it)

What sort of averaging do you intend doing?

The HP 8753/8720 VNAs use an Infinite impulse response (IIR) filter. It
means that one can take 1000 averages, without storing data for the last
1000 readings, so it is very memory efficient. However, I personally find
annoying as it always concerns me how long to wait before it's safe to take
a measurement, results from previous measurements are still in the output
data. I should sit down one day and read the documentation, or find out the
exact formula used, and work out a time for it to settle to 99% or
something. In practice, I rarely use averaging, but prefering to just
reduce the IF bandwidth.

But of course, averaging has its place - especially if doing an isolation
measurement during the calibration, but on the professional VNAs I never
feel the need to do that. On a profesional VNA, the only use of an
isolation measurement is if there is leakage *outside* the instrument, as
the isolation inside the instrument is good enough to make an isolation
measurement of no benefit. Of course the NanoVNA is different, and
isolation measurements and averaging probably play a greater role.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

I just released 0.0.10:


It's not the most exciting release, but it offers some quality of life
improvements, such as the ability to choose the font size (particularly
useful for Linux users, whose default is a massive 11 pt font).

It also adds debug logging: -d to get log messages to the terminal, or -D
filename.txt to log to a file. Useful if you see crashes!

Additionally, it now supports importing magnitude/angle touchstone files,
and there's been a number of little bugfixes.

As ever, I look forward to hearing what bugs you find, and what new
features you want! :-)

--
Rune / 5Q5R

Dear members,



I can't seem to connect to my usb serial port on my NANOVNA. I want to be
able to use the TAPR Vector Network Analyzer software Version 4.3 and when I
plug in my NANOVNA into my computer's USB port I comes up on the Device
Manager

As: Other Devices > ChibiOS/RT Virtual COM Port.



How do I get it to come up as a USB COM port. Do I have the WRONG Firmware
installed in my NANOVNA? None of the information I have been able to find
tells me how to cure this problem. Can someone on this website tell me
what I have to do to get this running?



Any suggestions on how to get this running appreciated.



73 Dave Hassall WA5DJJ Las Cruces, New Mexico

Website:

QRSS SUPER GRABBER WEBSITE:

On Wed, 18 Sep 2019 at 20:30, Rune Broberg <mihtjel@...> wrote:

Hi Bruce,
good to hear that it works! Averaging is on the roadmap, probably for
0.0.11 (or 0.1.0 or 1.0.0, however I name it)

What sort of averaging do you intend doing?

The HP 8753/8720 VNAs use an Infinite impulse response (IIR) filter. It
means that one can take 1000 averages, without storing data for the last
1000 readings, so it is very memory efficient. However, I personally find
annoying as it always concerns me how long to wait before it's safe to take
a measurement, results from previous measurements are still in the output
data. I should sit down one day and read the documentation, or find out the
exact formula used, and work out a time for it to settle to 99% or
something. In practice, I rarely use averaging, but prefering to just
reduce the IF bandwidth.

But of course, averaging has its place - especially if doing an isolation
measurement during the calibration, but on the professional VNAs I never
feel the need to do that. On a profesional VNA, the only use of an
isolation measurement is if there is leakage *outside* the instrument, as
the isolation inside the instrument is good enough to make an isolation
measurement of no benefit. Of course the NanoVNA is different, and
isolation measurements and averaging probably play a greater role.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

Hi Bruce,
good to hear that it works! Averaging is on the roadmap, probably for
0.0.11 (or 0.1.0 or 1.0.0, however I name it)

--
Rune / 5Q5R

Hi again Erik;

My apologies for misspelling your name on my earlier post. :-O

I re-flashed the 1500 MHz firmware this morning, and have observed no change in behavior. To ensure I'm not on a different page, the firmware build date I'm working with is Sep 14, 2019 - 10:38:20.

The re-flash also confirmed that the DFU software switch works fine, so the update was effortless. I also like that you implemented it as a two step process. I seem to have a propensity to accidentally touch something I shouldn't touch and send the device chasing its tail to places unknown. I often experience many restarts before I get to where I need to be. LOL! The Touch screen cal routine seems to work OK also.

I've been trying to get a better handle on the errors I'm seeing here, so it might be useful if I share what I think I have found that might help with debug... or maybe inspire some definitions to ensure my measurements are valid.

I reduced the display to a single trace... Only to keep my wits about me and not lead me off onto a tangent.... I stepped through each of the display formats in both cal and uncal modes and for both channels to verify expected results.

In channel O, LogMag and phase look fine. CH1 LogMag looks like indeterminate reflection data rather than gain (i.e. S22 vs S21).
Delay is not functional at all (in either CH0 or CH1 and the display is fixed at 1.0 seconds in both channels .
Smith, SWR, Polar, and linear all look OK.

I began to get inconsistent data when I began investigating the Real and Imag displays, so I tried a number of things to establish a starting point and baseline. Too much variability in those results to attempt mapping the process and incremental results here. The net of what I think is contributing to this is that the data is somehow getting corrupted when making display changes. I also discovered that Recall/Save now supports Recall only. Save is no longer an option perhaps? I am able to navigate to the Cal setup menu to initiate a Save when I wish to move stored data positions (Store 3 to Store 0 for example). This works OK so far, and as long as I don't modify the recalled data display in any manner prior to initiating the re-save. Since all results are computed from the corrected set of reflected and transfer coefficient data, I assumed that changing the saved display configuration would have no impact on the calculated results. Is this assumption incorrect? Are there post measurement display changes that invalidate the measurement results?

--
73

Gary, N3GO

Hi Herb,
the .exe releases will continue to be made, and the next one will be out
"soon" (maybe tonight, though it's getting late.)

--
Rune / 5Q5R

Ah. Correct. He did not refer to the model structure but used direct numbers in the code.

On Wed, Sep 18, 2019 at 07:35 AM, <erik@...> wrote:

Are you referring to the "open_model" data in the firmware?
I could not find any reference to that model in the firmware so I guess it is
not used.

Erik, I'm not sure if the NanoVNA-H code at
is the firmware you are referring to, but there is a 50 femtofarad capacitor in
the eterm_calc_es() routine in main.c.

I've attempted to hightlight (sort of) the specific line, below:

- Jeff, k6jca

eterm_calc_es(void)
{
int i;
for (i = 0; i < sweep_points; i++) {
// z=1/(jwc*z0) = 1/(2*pi*f*c*z0) Note: normalized with Z0
// s11ao = (z-1)/(z+1) = (1-1/z)/(1+1/z) = (1-jwcz0)/(1+jwcz0)
// prepare 1/s11ao for effeiciency
float c = 50e-15; <<<<<< 50 femtoFarad capacitance
//float c = 1.707e-12;
float z0 = 50;
float z = 6.2832 * frequencies[i] * c * z0;
float sq = 1 + z*z;
float s11aor = (1 - z*z) / sq;
float s11aoi = 2*z / sq;

// S11mo鈥?= S11mo - Ed
// S11ms鈥?= S11ms - Ed
float s11or = cal_data[CAL_OPEN][i][0] - cal_data[ETERM_ED][i][0];
float s11oi = cal_data[CAL_OPEN][i][1] - cal_data[ETERM_ED][i][1];
float s11sr = cal_data[CAL_SHORT][i][0] - cal_data[ETERM_ED][i][0];
float s11si = cal_data[CAL_SHORT][i][1] - cal_data[ETERM_ED][i][1];
// Es = (S11mo'/s11ao + S11ms鈥?)/(S11mo' - S11ms鈥?)
float numr = s11sr + s11or * s11aor - s11oi * s11aoi;
float numi = s11si + s11oi * s11aor + s11or * s11aoi;
float denomr = s11or - s11sr;
float denomi = s11oi - s11si;
sq = denomr*denomr+denomi*denomi;
cal_data[ETERM_ES][i][0] = (numr*denomr + numi*denomi)/sq;
cal_data[ETERM_ES][i][1] = (numi*denomr - numr*denomi)/sq;
}
cal_status &= ~CALSTAT_OPEN;
cal_status |= CALSTAT_ES;
}

David.

Given the big leakage at high frequencies, would iisolation calibration work there anyway?