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On Fri, 27 Sep 2019 at 21:42, Warren Allgyer <allgyer@...> wrote:

Mike,

The do indeed increase the dynamic range somewhat. The dynamic range at
600 MHz and above is rated at 40 dB and all of the units I tested , even
the worst ones, met this spec. I have no uses for which I need dynamic
range greater than 30 dB. For example, a return loss of 30 dB equates to a
VSWR of 1.07 to 1. Trust me..... if I can achieve 1.07 to 1, even for my
broadcast clients, I have no need to go further.

Warren,

Dynamic range of a VNA is a parameter of importance in *transmission*
measurements, if for example you are looking at the attenuation of a
filter.

My HP 8720D has a measured dynamic range of about 108 dB (specification is
100 dB), but I found that insufficient for some measurements, making them
frustrating slow.

The Keysight N5242B



has a dynamic range of 127 dB, but it would not be able to measure a return
loss of even 60 dB, and even 50 dB would pose real challenges.

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

John,?
Very interesting and stuff.??
Thanks,Mike WY6K


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

I have now upgraded my NanoVAN with the NanoVNA-H__800_ch_20190924.dfu firmware.
However, as the attached picture show there is not much real change

My understanding is that flashing Nano**800_aa*.dfu
("aa" instead of "ch") is needed for changing max frequency.
Then load "ch" version for that functionality..

Hi one suggestion , why not export the traces on s2p format and plot the traceto be compared , using the Avago
program APPCAD ?
Best Regards
IZ1MDJ Maurizio

On Sun, 29 Sep 2019 at 17:40, Jeff Anderson <jca1955@...> wrote:

On Sun, Sep 29, 2019 at 03:43 AM, Dr. David Kirkby from Kirkby Microwave
Ltd wrote:

The 85032F is not one of Keysight’s best kits.

Hi Dave,

You are probably right. I chose this kit because, of the 50-ohm cal-kits
listed by Keysight as supported for the 8753D, it seemed to have the worst
higher-order capacitance terms, thus a good choice for testing my theory.

I don’t know if you have an 85032F, but if you do, you will find the male
and female opens have the same coefficients in your 8753D. But Agilent
later revised the coefficients, with different ones for the male & female.

It would be interesting to know what errors you get with your simplified
model for the 85050B 18 GHz APC7 calibration kit.

Ask and you shall receive!

First, Keysight's values defining the 85050B open:

C0 = 90.4799e-15;
C1 = 763.303e-27;
C2 = -63.8176-36;
C3 = 6.4337e-45;
Delay_Open = 0;
Loss_Open = 0;
Offset_Zo_Open = 50;

Now, the results of my calculations...

1. Open using C0 - C3 : rho = 1.0000, theta = -4.9381 degrees

2. Open using only C0: rho = 1.0000, theta = -4.8830 degrees
(Note: the angular delta between the two thetas is 0.055 degrees)

Yes, the difference of 0.055 degrees at 1500 MHZ is small compared to the
0.3 degree uncertainty of the standard

I accept that C0, Z0 and delay are sufficient for any of the Keysight kits
you have tried, and I expect any others too.

Having support in firmware for this would be really good for anybody, like
myself, who is keen to use the NanoVNA standalone for use outside on
antennas, not in conjunction with a PC.

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

Hi

I have now upgraded my NanoVAN with the NanoVNA-H__800_ch_20190924.dfu firmware. However, as the attached picture show there is not much real change except that the abnormality has moved down in frequency. Is it the right firmware I have loaded since I can set a stop frequency to 900 MHz. I didn't expect that.

Thanks Warren for clarifying the use of the harmonics in the NanoVNA. I don't know the NanoVNA anatomy as well as I know the RFzero. They are indeed nice devices.

Bo

Thanks uni berry, that was exactly the problem. The Kaspersky "File Anti Virus" button has to be turned off for NanoVNA-Saver to launch which it does after that. Before I ran NanoVNA-Server, I scanned it with the Kaspersky virus scanner and it was clean. I wonder what it is that Kaspersky doesn't like about launching the application.

I used a few LP filters and a mobile V/UHF antenna to test the NanoVNA against a $$$ analyzer:

Gabriel,
Hugen posted last night that a 3.5" display could still be part of the final design. The NanoVNA has been really well received but one of the most requested feature updates has been a larger display. The 4.3" NanoVNA-F is selling at a price point about twice the NanoVNA primarily on the basis of its larger display. If your cost point cannot be changed to incorporate a larger display, then hopefully the STM32F303CCT6 will have enough space for both Chinese characters and large English font to make the display more readable.

On Sun, 29 Sep 2019 at 07:28, Starsekr via Groups.Io <Starsekr=
[email protected]> wrote:

On Sat, Sep 28, 2019 at 03:49 PM, Dr. David Kirkby from Kirkby Microwave
Ltd wrote:

I don’t think your simple model is really suitable for the following
reasons

1) The variation of C with homemade standards is likely to exceed that of
commercial standards - this is from experience measuring them.

2) The inductance of shorts is likely to be more with homemade standards
than commercial ones - again this is based on experience measuring them.

3) People may well want to make measurements in a 75 ohm system.

4) it is possible to improve upon the accuracy of loads at low

frequencies

by using a DC resistance measurement.

5) In the case of a female N, a simple standard can be made by just

leaving

the connector open. This will create a higher impedance transmission line
than 50 ohms as the centre conductor sits in a cylindrical section with a
greater diameter than when its mated.

6) The loss of homemade standards is likely to be greater than commercial
ones from Keysight - again this is based on actual measurements I have
performed.

Dr. Kirkby, if I understand your post, and objections to Dave Anderson's
"Very Simple Characterization Model", You are against Mr. Anderson's idea
because it doesn't account for the possibility that inductance, capacitance
and loss terms are likely to be significant in home-made standards and a
desire to have an option to change the reference resistance to account for
actual load resistance, or to use the VNA at something other than 50 ohms,
but you agree with the idea that Offset Delay should be an input option.

Yes, essentially

Dr. Kirkby, I too like the idea of being able to reference the NanoVNA with

75 ohms or measureing a home-made load with a 4 terminal system and getting
a more accurate result. But I'm not sure if your other objections are
valid (1) (2) (6), because most home-made loads won't be characterized
anyway. The operator will take the answer he gets, publish it in QST or
RadCom, and move on.

I believe implementing the full model could be beneficial for homemade kits
in *some* circumstances, such as

* Have the ability to measure homemade standards at work. I would suspect
that a fair few NanoVNA users work in the RF field.

* Know someone with a VNA able to measure them

* *Possibly* compute the properties using a software package like openEMS



* *Possibly* compute the approximately properties, then tweak them to
produce the best calibration possible by using the T-checker.



Jeff has convinced me that for the HP kits, C0 is sufficient.

I think we can all accept the possibility of making slight tweaks of the
load based on 4-wire resistance measurements, are the possibility of
working in 75 ohms.

*ONE OTHER THING I HAD FORGOTTEN ABOUT IS THE NEED TO BE ABLE TO ENTER THE
DELAY OF A THRU FOR A 2-PORT CALIBRATION *

Of course this brings up the operations of data entry and storage; which
starts taking away from the original concept of turn it on, do a simple
1-2-3 cal, and use it, so I think that option should be 1st choice in the
software.

If the firmware could

a) Define a number of calibration kits
b) Default to the most used one

then once the VNA is configured once, the rest would be a simple 1-2-3.

There seems a good argument for the VNA defaulting to the parameters of the
supplied kit (50 fF on the open, some small negative delay on the short).
But I would like to override that, as I will never use the supplied kit, as
it’s impossible to avoid rotating the male pin in the female.

Jim McEwen, KA6TPR


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

As an update.

The seller has kindly updated the post and even going to give a donation to a good cause. They have lots of good feedback on eBay, so I assume the quality is good. So I have no issue at all with it.

Interesting: Does the use of the ADF4350 mean the minimum frequency will be
137MHz+? Or do you have plans for handling that?

Are you and your project associated to edy555/ttrftech, to hugen, or to
neither?

--
Rune & 5Q5R

On Sun, 29 Sep 2019 at 19:22, Gabriel Tenma White <OwOwOwOwO123@...>
wrote:

Hi, NanoVNA V2 layout designer here. Here is what I know:
* V2 won't have a bigger display because it is too expensive
* frequency range will go to at least 3.5GHz; PLL limit is 4.4GHz.
* ADF4350 is used because of cost reasons; ADF4351 is more expensive by a
factor of 5.
* The layout is already fairly packed, so modular is not possible without
a huge form factor.
* Layout and shielding are much improved for higher dynamic range.
* Price will be around the same as the existing NanoVNA. The design is
already cost limited, so we can not do anything that will further add cost.
* PC interface will be completely reworked. A binary protocol will be used
similar to the xaVNA (we are going for full compatibility with the xaVNA PC
software). If you are writing custom PC software for the Nano, please make
sure the USB interfacing part is well abstracted away and easy to change.

The development timeline is going to be pretty long (by Chinese standards
at least). We will iterate on PCB layout to get the best dynamic range. I
think we might see initial (quantity limited) sales in ~3 months.

Forgot to mention...the 85050B’s calculation were for 1500 MHz (corrected this -- I'd originally typed 900 MHz)

- Jeff

This post is somewhat off topic but I am so happy with what I achieved I felt I earned some bragging rights

For those that need a nanoVNA V2 for tuning their 2GHz antennas there is no real reason to wait.
If you have a close look at the attached picture you will notice the main nanoVNA V2 components in a home build.
In the middle back-to-back are two ADF4351 modules. On top of the aluminium bar on the left is the 0.1MHz till 3GHz bridge and on the right is a PCB with three IAM81008 mixers dead-bug style. All controlled by an Arduino zero hiding at the top. Audio goes to a line in of a PC and that is all you need for a GHz VNA.
With this home build VNA I was able to solve a problem of my home build 2GHz Spectrum Analyzer that is hiding underneath the VNA.
The aluminium bar at the bottom of the picture is actually a 5 resonator interdigital cavity filter. I have been trying to buy one for a long time but as I wanted to convert the 2GHz first IF of the SA directly to the second IF at 10.7MHz I was not able to find one narrow enough and finally decided to build it myself.
So I first had to build the 35MHz till 3GHz VNA, just like the NanoVNA V2 (although not so portable)
The construction of the cavity filter proved to be doable without any special tools except a 4mm tap. The aluminium bar for the housing and the copper rods for the resonators can be bought cheaply per meter.
Tuning the cavity filter proved to be more difficult than expected as there is absolutely nothing that gets thru if out of tune. So I used a simple trick that is of interest only for people that want to build their own cavity filter and now it works!
Center frequency 2019MHz, 2dB bandwith 4MHz. Better than -70dB at 10MHz offset. Passband attenuation is -7dB
The spectrum analyzer has hardware RBW filters at 300kHz and 30kHz (top tin box at right) and a log amplifier (top tin box at left) and variable FFT stitching RBW filters to a minimum resolution of 1Hz. IIP3 is +17dBm and noise floor at 300kHz BW is around -100dBm.
To prove it is working I added a 0 to 1GHz scan of the spectrum around my house using a small antenna. You will notice the FM and DAB transmitters and the rather strong cell phone base stations
Again apologies for the off topic post.

Erik, PD0EK

Steve,
That's good information. Some Linux user's with bricked devices may not have been aware that a Windows PC might be able to recognize the device (if they still had a Windows PC available) and un-necessarily ordered the ST Programmer.

reply to kb3cs
That's certainly annoying.
I'd like to have a reference for where these regulations abide.
Do you have it handy?

thanx
W5VZB

On Sun, Sep 29, 2019 at 04:16 AM, Kurt Poulsen wrote:

Hi Kurt,

Thanks for the reply.

My humble opinion is like your indications that L and C coefficient are not
relevant for the calibration kit delivered with the NanoVNA and in particular
as we have no idea if the kit are the same for all deliveries.

Agreed.

Until there is a full blown calibration kit definition embedded in the NanoVNA
this is the way forward to use the NanoVNA-saver.

Agreed.

again my opinion is that would be an overkill for the majority of NanoVNA
users. It is far better to focus on how and with simple means to find the
needed delays for a homemade kit or e.g. a BNC kit bought from SDR kits where
all these data are supplied with the kit.

Agreed. Describing how to characterize a homemade BNC kit would be a great idea.

I did measure the
supplied kit based on calibration by my HP 3.5mm kit on another VNA and I will
repeat and publish the result for those values to be entered in NanoVNA saver.

Kurt, that would be excellent! I'm looking forward to seeing these values

Best regards,

Jeff, k6jca

I finally got mine unbricked using "conventional" methods.

Here's the story:

1) Used ubuntu dfu-tool to load CLEAR_MEMORY_DFU.dfu . That left the NanoVNA white screened.
2) Tried to use dfu-tool to load a NanoVNA dfu. Couldn't: ubuntu no longer found NanoVNA, even in boot mode.
3) Installed DfuSe Demo on Windows.
4) Plugged NanoVNA into Windows box, in boot mode (2 pins shorted). Windows Search found and installed the STM driver (on the 3rd try). After that, Windows device manager always found the NanoVNA when in boot mode.
5) Used DfuSe to install the current NanoVNA dfu using Hugen's excellent instructions at . The important thing is that you are -upgrading-, not -uploading-. Use the Choose and Upgrade options on the right side of DfuSe.

Steve

Steve,
The following is what another user wrote:

// Begin Quote //

There are two ways to update firmware: DFU and ST-LINK. So, it depends on what method you're want to use.

1) DFU update. This is simple but not reliable way. If something will going wrong, you may brick your NanoVNA with this method and the only way to restore it is to update firmware with the second method. DFU method doesn't requires any special hardware and you can update it just through USB.

For DFU method, you will need the file with DFU extension: e.g. "nanoVNA_900_ch_20190920.dfu"

In order to upload it into NanoVNA you will need DfuSe software.

You will need to power-off your NanoVNA, connect USB to PC, short BOOT jumper with tweezers and power on NanoVNA. It will be booted in DFU mode. The display will be white. Now you can release BOOT jumper and then use DfuSE Demo tool to upload firmware file into NanoVNA.

2) ST-LINK update. This is native and reliable way. But it requires a ST-LINKv2 dongle. This dongle allows to flash even bricked device and also allows to use in-circuit debugging.

For ST-LINK update, you will need the file with HEX or BIN (any of these) extension: e.g. "nanoVNA_900_ch_20190920.hex"

In order to upload it into NanoVNA you will need ST-LINK Utility software.

You will need to connect ST-LINK to NanoVNA with 4 wires:
- 3.3V to VDD,
- GND to GND,
- SWDIO to SWDIO,
- SWCLK to SWCLK

There is no need to solder, you can just connect wires to the pads and press it with finger during upload. Then you will need to use ST-LINK Utility tool with the following memory parameters:
- Address: 0x08000000
- Size: 0x20000
- Data Width: 8 bits

I strongly recommend to save your current firmware before update. Just in case. Both software tools allows it. "

// End Quote//

After having read the above, I bought a second nanoVNA and use it as a sacrificial device when trying upgrades. I haven't had any problems upgrading with DFUSe Demo through USB, but I'm prepared in-case Murphy decides to pay me a visit.


Herb

It's alive !

For anyone patient enough to be following this, here's what happened and what fixed it:

1) Used ubuntu dfu-tool to load CLEAR_MEMORY_DFU.dfu . That left the NanoVNA white screened.
2) Tried to use dfu-tool to load a NanoVNA dfu. Couldn't: ubuntu no longer found NanoVNA, even in boot mode.
3) Installed DfuSe Demo on Windows.
4) Plugged NanoVNA into Windows box, in boot mode (2 pins shorted). Windows Search found and installed the STM driver (on the 3rd try). After that, Windows device manager always found the NanoVNA when in boot mode.
5) Used DfuSe to install the current NanoVNA dfu using Hugen's excellent instructions at . The important thing is that you are -upgrading-, not -uploading-. Use the Choose and Upgrade options on the right side of DfuSe.