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Nanovna-F is here

 

Oh...... my....... GOODNESS!!!

I love Nanovna original. I have three of them. But Nanovna-F just arrived and it is simply fantastic. It is heavy, thick, completely encased in aluminum and it has a huge, gorgeous 4.3 inch screen that I can see easily without reading glasses. It feels like comparing an S Class Benz to a Prius. Both are fantastic vehicles but...... well..... who would take the Prius.

Easily a 50 dB dynamic range at 1 GHz. Comparison tests to come but I can already tell it is at least the equal of the little brother.

Did I mention the screen? Just wonderful and I got it for $116.

WA8TOD


Re: SOLT calibration vs. TRL

 

True, however, I was thinking forward as I understand a 3 channel nano receiver is under development. Further, the technique for obtaining true 2 port s data currently requires unbolting the test device and turning it end for end. Not sure the calibration in that process would hold up. Thoughts? Unless a simple after market S parameter test set is developed.


Re: SOLT calibration vs. TRL

Dr. David Kirkby from Kirkby Microwave Ltd
 

On Tue, 15 Oct 2019 at 20:28, Dr. David Kirkby <
drkirkby@...> wrote:


TRL calibration requires a VNA with 4 receivers. The HP 8753 series, which
have 3 receivers, can perform something HP refer to as TRL*. This requires
a good match at the test ports - typically 6 to 10 dB on each test port. It
is not as good, but it is not possible to do true TRL calibration on a
simple VNA.
What I meant to say is that when using TRL* calibration on an HP 8753, 6
to 10 dB attenuators need to be added to the test ports of 8753 VNAs.

The 8720D instrument I have, was available with an optional 4th receiver to
allow full TRL calibration. It was option 400 and quite expensive. My
instrument doesn¡¯t have that capability.

Also a full S-parameter test set is needed.

I don¡¯t believe that TRL, or any similar calibration procedure, will be
possible with a simple VNA.

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


Re: SOLT calibration vs. TRL

Dr. David Kirkby from Kirkby Microwave Ltd
 

On Tue, 15 Oct 2019 at 19:11, alan victor <avictor73@...> wrote:

The group has been focused on SOLT or so called SOLM (match) for
calibration. However, for various reasons the TRL; Thru, Reflect, Line
calibration algorithm would be advantageous. Fabrication of such a kit
usually requires at least 3 lines to be built plus one fixture piece and
microstrip is not difficult using a straight edge and an Exacto blade
knife! The TRL lends itself to NON INSERTION components. In another words,
non coaxial elements. Just a thought and the copy below hints to the
benefits.

From Keysight:

TRL calibration requires a VNA with 4 receivers. The HP 8753 series, which
have 3 receivers, can perform something HP refer to as TRL*. This requires
a good match at the test ports - typically 6 to 10 dB on each test port. It
is not as good, but it is not possible to do true TRL calibration on a
simple VNA.

I don¡¯t think anything other than SOLT is likely to be practical on the
NanoVNA.

Actually, waveguide calibration is possible too, but waveguide is not very
useful under 1.5 GHz.

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


Re: A simple, and reasonably accurate way of simply entering the properties of WELL ENGINEERED calibration kits.

Dr. David Kirkby from Kirkby Microwave Ltd
 

On Tue, 15 Oct 2019 at 19:51, Jeff Anderson <jca1955@...> wrote:

Some of us have commercial cal kits for which C0 (as well as C1-C3) and
the delays are specified by the manufacturer. In my opinion, C1-C3 are
unnecessary for the NanoVNA's frequency range, but it would be great if the
basic NanoVNA handled, at a minimum, let the user enter C0 and delay for
the open as well as delay for the short.

As for verifying the value of C0 for calibration kits that have not been
characterized by their manufacturer, I believe there is a method for doing
this. And I think Kurt Poulson is the one who knows how to do it.

- Jeff, k6jca

The best way to do this is to perform a calibration then measure the
properties of a very good transmission line shorted at the end. The
amplitude should be constant with frequency. Errors will cause a ripple
But that requires good calibration standards, in addition to

However, for initial testing of software, that is unnecessary. If one
performs two calibrations

1) A delay of 40 ps and a fringe capacitance of 30 fF

2) A different (longer) delay and a fringe capacitance of zero

should give very similar results if the longer delay is suitably chosen.
There is a mathematical relationship between a small change in capacitance
and offset length. So no hardware is needed.


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


Re: A simple, and reasonably accurate way of simply entering the properties of WELL ENGINEERED calibration kits.

Dr. David Kirkby from Kirkby Microwave Ltd
 

On Tue, 15 Oct 2019 at 18:06, QRP RX <qrp.ddc@...> wrote:

On Tue, Oct 15, 2019 at 07:50 PM, Dr. David Kirkby from Kirkby Microwave
Ltd wrote:


I don¡¯t doubt that the C0 is useful
you already can setup delay with DISPLAY - SCALE - ELECTRICAL DELAY menu.

If you needs C0 settings, just explain me how to test that it works
properly? I will add such settings if it really helps.

Unfortunately setting the delay after calibration with

DISPLAY - SCALE - ELECTRICAL DELAY menu.

will not give good results for many connectors - in particular for N
connectors.

The reason is because that only changes the phase, which is what happens if
you move along the transmission line.

Unless

* A delay of the short calibration standard
* A delay of the open calibration standard
* A capacitance of the open calibration standard (as a minimum C0).

are all set up *before* the calibration commences, the calibration will not
be good. There will be both amplitude and phase errors. Those errors can
not be corrected by just changing a delay.

The lack of delays doesn¡¯t present a problem with female SMA connectors, as
the delay of the male short and male open are very close to zero. But it
will cause problems for most others connectors.

The correct sequence of events should be

1) The user specifies the properties of the calibration standards (delays
and capacitance)

2) The calibration standards are measured by the VNA

3) The error terms are computed.

4) All measurements are corrected using the error terms.

Would you be able to implement something that allows the user to save a few
calibration kits? Four should be enough for anyone. It would be good if the
user could name the kits - eg, SMA, N, BNC, 7-16 etc, but if not simply
CALKIT 1, CALKIT 2 etc would do.

Note that the male and female connectors are generally different. It is
normal nowadays to specify

SHORT -M-

to mean the male short calibration standard.

I can find relevant equations.

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


Re: A simple, and reasonably accurate way of simply entering the properties of WELL ENGINEERED calibration kits.

 

Some of us have commercial cal kits for which C0 (as well as C1-C3) and the delays are specified by the manufacturer. In my opinion, C1-C3 are unnecessary for the NanoVNA's frequency range, but it would be great if the basic NanoVNA handled, at a minimum, let the user enter C0 and delay for the open as well as delay for the short.

As for verifying the value of C0 for calibration kits that have not been characterized by their manufacturer, I believe there is a method for doing this. And I think Kurt Poulson is the one who knows how to do it.

- Jeff, k6jca


SOLT calibration vs. TRL

 

The group has been focused on SOLT or so called SOLM (match) for calibration. However, for various reasons the TRL; Thru, Reflect, Line calibration algorithm would be advantageous. Fabrication of such a kit usually requires at least 3 lines to be built plus one fixture piece and microstrip is not difficult using a straight edge and an Exacto blade knife! The TRL lends itself to NON INSERTION components. In another words, non coaxial elements. Just a thought and the copy below hints to the benefits.

From Keysight:

==============================================
A vector network analyzer requires that a measurement calibration be performed before error-corrected measurements can be made. For two-port measurements, the calibration algorithm used will determine the appropriate calibration kit, known either as SOLT or TRL/TRL*.

Traditional full two calibration calibration typically utilizes three impedance and one transmission standards to define the calibrated reference plane. These standards, typically a Short, Open, Load, and Thru, make up the SOLT calibration kit.

Another two port calibration type utilizes a minimum of three standards to define the calibrated reference plane. The measured parameters of the Thru, Reflect, and Line standards in a TRL/TRL* calibration kit provides the same information as a SOLT calibration via a different algorithm.


Depending on the availability of calibration standards and the functionality of the network analyzer, one may use either calibration kit.

In many non-coaxial , SOLT calibration standards are difficult, if not impossible, to build. The non-availability of calibration standards in proprietary or unique coaxial connectors also benefit from the TRL/TRL* calibration method.

============================================


Re: Newbie questions

 

Hi Mel,Use this free Android app with the nanoVNA:
?
You will need to ensure your kindle has OTG USB and the proper cable adapter.
Regards,Larry

On Tuesday, October 15, 2019, 1:39:28 p.m. GMT-4, Mel Farrer, K6KBE <farrermesa@...> wrote:

More on getting started, I have a laptop fine, can the Saver be downloaded to a Kindle Fire for portable use?? Just a question.? On a ladder in the antenna range the Kindle is a lot smaller.

--
Mel, K6KBE


gnuplot for nanoVNA Touchstone files

 

link added to application notes
/g/nanovna-users/wiki/Application-Notes


Re: Newbie questions

Mel Farrer, K6KBE
 

More on getting started, I have a laptop fine, can the Saver be downloaded to a Kindle Fire for portable use? Just a question. On a ladder in the antenna range the Kindle is a lot smaller.

--
Mel, K6KBE


Re: A simple, and reasonably accurate way of simply entering the properties of WELL ENGINEERED calibration kits.

 

On Tue, Oct 15, 2019 at 07:50 PM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:


I don¡¯t doubt that the C0 is useful
you already can setup delay with DISPLAY - SCALE - ELECTRICAL DELAY menu.

If you needs C0 settings, just explain me how to test that it works properly? I will add such settings if it really helps.


Re: Upgrade MCU from STM32F072C8T6 to STM32F303CCT6

 

Nice enhancement.I'll add this to my Console command document, specifying your version of firmware.
Regards,Larry

On Tuesday, October 15, 2019, 12:30:41 p.m. GMT-4, QRP RX <qrp.ddc@...> wrote:

On Wed, Sep? 4, 2019 at 08:35 AM, Rune Broberg wrote:


it is a USB serial port, and I'm happily
running it at 115200 in my software with few problems. There is the
occasional single-bit/byte transmission error
TLDR: The USB driver negotiates the speed, higher speeds are fine.
The speed which you set for NanoVNA COM port doesn't matter. The speed value is just not used. No matter what speed you choose, it always communication at maximum speed.? :)

If you have trouble with occasional transmission error. Try this firmware, it should solve your issue:

It also has scanraw command, it allows to perform measurement for unlimited amount of points, and with using average up to 1000x. But it returns raw measured values, with no calibration apply. So, you're needs to apply your own calibration to the result.

For example this command will return you S11 measurement (with no calibration apply) from 50 kHz to 10.050 MHz with 1 kHz step (10000 points) and with 5x average:

scanraw 0 50000 1000 10000 5

where
0 - channel CH0
50000 - start frequency
1000 - frequency step
10000 - needed point count
5 - average times


Re: Upgrade MCU from STM32F072C8T6 to STM32F303CCT6

 

On Wed, Sep 4, 2019 at 08:39 AM, Rune Broberg wrote:


I did check earlier that STM32F104 should be a direct drop-in, and offers
slightly more RAM (20kB) and 128kB of flash memory at the max spec.
NanoVNA already uses STM32F072CB which has 128 kB flash and 16 kB RAM.
NanoVNA uses end of 128 kB flash block to store configuration and calibration data.
So, if your NanoVNA can store and restore calibration, it already has 128 kB flash. :)


Re: A simple, and reasonably accurate way of simply entering the properties of WELL ENGINEERED calibration kits.

Dr. David Kirkby from Kirkby Microwave Ltd
 

On Tue, 15 Oct 2019 at 14:12, Jeff Anderson <jca1955@...> wrote:

On Tue, Oct 15, 2019 at 02:39 AM, Dr. David Kirkby from Kirkby Microwave
Ltd wrote:


Using a delay of 31.78 ps for the open, rather than the published 29.24
ps,
resulted in an phase of 0 +/- 0.1 degrees.
Using a delay of 31.78 ps for the short, resulted in an phase of 180 +/-
0.1 degrees.
Dave, very interesting.

But I'm a bit confused by the part I've quoted, above. It seems to me
that the measured angles should be on the order of (very roughly) -34 and
+146 degrees for open and short, not a perfect 0 and 180.

No I meant what I said. The reason for the disparity is that I had moved
the reference plane to a location I should have theoretically got a phase
of 0.

Here¡¯s a photograph of the screen taken under the following conditions

* HP 8720D VNA
* Calibrated from 50 MHz to 10 GHz with an 85052B 26.GHz 3.5 mm calibration
kit.
I used short, open and fixed load, not the sliding load, which is more
accurate but time consuming.
* The 85052B kit has the same open and short parameters as the 9 GHz
85033D and 85033E kits. (One of the Agilent guys wrote on their forum that
the *standards are identical* - it is only the label and price which are
different???)
* Calibration coefficients used directly from the firmware of the VNA.
* Attached male open
* Applied a port extension of 31.79 ps, which is the delay of the short
standard. So I had moved the reference plane.
* The scale on the VNA has 0 degrees in the centre, with 0.25 degrees pet
division.
* The departure from the expected 0 degrees from an ideal open is 0.133
degrees at 1.5 GHz, rising to no more than 0.9 degrees anywhere over the
range from 50 MHz to 10 GHz.

I just ran a calculation in Matlab for the 85033D/E kit (Male). At 1.5
GHz, the OPEN with Full Definition should have a phase shift of -34.19
degrees.

I had moved the reference plane by an amount I would have expected to see 0
degrees at all frequencies.

Setting C0-C3 to 0 and making the open's delay equal to the short's delay
changes this angle to -34.35 degrees, or an error of about 0.16 degrees,
which is pretty insignificant. So this seems to support your idea.

I measured 0.133 degrees. The uncertainty of the measurements far exceeds
that.



However, things change for an N cal kit. I ran the numbers for an 85032B
Male cal kit, and at 1500 MHz there is an error in the Open's phase of
about 3 degrees (from -22.15 to -19.22 degrees) if you set C0-C3 to 0 and
set its delay equal to the short's delay. Pretty significant.

Yes, agreed.

If you have the 85054Bs parameters in, I would be interested what you get.
That¡¯s a much more expensive kit. But ultimately small departures from the
ideal 180 degrees makes no practical difference, do three is no
overwhelming reason to believe that the phases of the opens are going to be
very close together.


Also -- I think one might want to keep the C0 term for the Open. I was
reading one of Kurt's documents, and I believe there is an asymmetrical
offset to an uncompensated Open's Smith Chart pattern when an Open is
connected to a VNA through a length of very low-loss line (0.5 meters?).
One can reduce this asymmetry by adding the C0 capacitance term to the
Open's definition. But I might be misremembering.

I don¡¯t doubt that the C0 is useful, but if there is very little memory
available, and an even simpler model might be workable, but the 85032B kit
is a very popular kit, so one would not want to do anything if it messes
that kit up.



- Jeff, k6jca
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


Re: Upgrade MCU from STM32F072C8T6 to STM32F303CCT6

 

On Wed, Sep 4, 2019 at 08:35 AM, Rune Broberg wrote:


it is a USB serial port, and I'm happily
running it at 115200 in my software with few problems. There is the
occasional single-bit/byte transmission error
TLDR: The USB driver negotiates the speed, higher speeds are fine.
The speed which you set for NanoVNA COM port doesn't matter. The speed value is just not used. No matter what speed you choose, it always communication at maximum speed. :)

If you have trouble with occasional transmission error. Try this firmware, it should solve your issue:

It also has scanraw command, it allows to perform measurement for unlimited amount of points, and with using average up to 1000x. But it returns raw measured values, with no calibration apply. So, you're needs to apply your own calibration to the result.

For example this command will return you S11 measurement (with no calibration apply) from 50 kHz to 10.050 MHz with 1 kHz step (10000 points) and with 5x average:

scanraw 0 50000 1000 10000 5

where
0 - channel CH0
50000 - start frequency
1000 - frequency step
10000 - needed point count
5 - average times


Re: Upgrade MCU from STM32F072C8T6 to STM32F303CCT6

 

Fantastic!!!
This opens up the possibility of a whole new round of firmware-based functional enhancements for this device.
Thanks for the effort.
It would be great if you could upload a few photos of the mod to the Hacks and Mods folder in the Files area and maybe give some info on where you obtained the replacement uP from and price.

Regards,Larry

On Tuesday, October 15, 2019, 11:55:21 a.m. GMT-4, Ken Liao, AA6KL <kuohsing@...> wrote:

I have successfully ported the NanoVNA firmware to support STM32F303CCT6.? The detail can be found at



The minimum required hardware mod is to replace the MCU and add a 1.5K ohm resistor between USB_DP and VDD, or between USB_DP and PA10.

If you have the chance to try the code, please let me know if you see any issue.

Ken


Re: errors of "error" models

 

#48 : ann : update 3 of [LeastVNA] is withdrawn

Hello,

After the comments made by Gary O'Neil on
9 October 2019:

/g/nanovna-users/message/4483

which resulted to our:

41 : Corrections and Confirmations to
40 : [LeastVNA] - Update 3 - 9 October 2019
/g/nanovna-users/message/4519
Thu, Oct 10, 2019 at 11:59 AM :

where we specifically admitted that:

| Well, after all that, which are in addition to those, yet
| unpublished, weaknesses we already noticed, it seems
| that at least another one Update of our [LeastVNA]
| description is unavoidable...

we found that we have to make major changes
to our [LeastVNA] and thus to upgrade it as a
whole, so we withdraw its update 3, as well as
* a n y * other previous edition of it.

Sincerely,

gin&pez@arg

48#


Re: Another ebay deal?

 

On Thu, Oct 3, 2019 at 05:43 PM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:


I am not saying that the Chinese board is totally useless, but for a PCB
with connectors that have quite a limited lifetime, and a small number of
cheap components, it seems quite expensive to me.
yes, exactly. The price is inadequate very expensive. The real price for such board is 2-5 usd. But they sell it for 30 usd, this is crazy price for the bord with just a connectors with no elements, and these connectors are rated for 20-time use. That's crazy.


Re: Upgrade MCU from STM32F072C8T6 to STM32F303CCT6

 

I have successfully ported the NanoVNA firmware to support STM32F303CCT6. The detail can be found at



The minimum required hardware mod is to replace the MCU and add a 1.5K ohm resistor between USB_DP and VDD, or between USB_DP and PA10.

If you have the chance to try the code, please let me know if you see any issue.

Ken