开云体育

Hi Jeff
I have given a report I made on the last day of 2017 a brush-up which you can download from
to design a homemade male BNC calibration kit.pdf
It is a full blown how to and if someone else seems it is overwhelming the trick is to calibrate to the rear of the adaptor and use 0ps for short, the fringe C for the open simulated in my report and the tuned shunt C for the load. That is a good starting point. Then check the calibration with a semirigid cable or a BNC test cable of length 0.5 meter until the S11 dB trace run without oscillation. Then you measure S11 in a super way an to "hell" with the measurement plane is not the defined calibration plane for the BNC adaptor :) If the NanoVNA could provide a negative Electrical delay it could be fixed.
To all !!! Please note and respect the reservations I have made at the end of the report
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af Jeff Anderson
Sendt: 29. september 2019 19:04
Til: [email protected]
Emne: Re: [nanovna-users] Cal-Kit Standards' Definitions

Dr. Dave

I already noted that you cannot see the -60 dB point on a filter in through mode with a dynamic range of 40 dB. And I already noted that 99% of the time I personally do not need to see the 60 dB point and that for the 1% I can add an amp to the source.

You may well need to see that at Kirkby Microwave Ltd,/drkirkby@.../ 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. And that is likely why you have equipment available to do so. And I am glad you have such equipment because between talking about that and your self promotion there is very little meat left in your posts.

The vast, vast majority of the people on this board have no need for that level of detail.

Sheesh! Give it a rest will you?

WA8TOD

In my opinion, it could be a bit larger with a larger screen and still be fine for portable or field use.? Just look at the Keysight Field Fox...
Mike WY6K


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

It's somewhat different, does not really matter
Till 300MHz both test signal and 5kHz offset LO are fundamentals.
From 300 to 900MHz test signal is 3rd harmonics so actually from 100 to 300MHz and the LO is using 5th harmonics so actually is from 60 to 180MHz.

More ideas.

If possible query the firmware name and version.

When, if, possible set the max fundamental frequency.

Possibility to load Elsie data. The problem right now is that Elsie doesn't export S-file data otherwise it would be possible. So should Elsie add S-data OR should NanoVAN-Saver be able to load Elsie data, i.e. who to ask for a change? (I have not tried with RFSim99 data). The overall idea is to be able to show simulation vs measured responses.

Bo

..... and eliminate all of that self promotion? Highly unlikely I think.

WA8TOD

Hi

Personally I am not at all sensitive to the form factor. My use is 99% lab use and 1% antenna/portable use.

I wonder how many actually wants a small form factor.

Bo

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