¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. Nanovna-Users
  2. Messages
Expanded Topics Messages
Date
Re: errors of "error" models

 

#90.01 : Final Conclusion
-
#90.00 : A Practical Introduction to our -Second- Arithmetical Method
of Error Estimations in VNA Measurements : [SAMEEVNAM]
22 December 2019 - /g/nanovna-users/message/8505

Hello,

Allow us, please, to conclude from the last two lines of the computed
arithmetical results:


as well as, from their graphical representation:




that in this particular instance, the Least Core Uncertainty
-
that is the component of the Uncertainty which is propagated only by three
HP Standards to the results of Zt measurement using our [NanoVNA] System
-
is arithmetically estimated to be more than:

( Rt : +5% , Xt : +13% )

Sincerely,

gin&pez@arg

#90.01:
Re: QEX Magazine #tutorials

 

All,

Just know that *soon* all ARRL members will have electronic access to QEX and NCJ issues via the ARRL.org website, although print issues will still require a subscription.

And, be aware that there IS the Fair Use provision in the copyright law. You do NOT need permission to quote a copyrighted work with source citation for limited and reasonable amount. Others have cited the appropriate legal source. I suspect Phil, that in your large dissertation (mine was two volumes), you quoted numerous sources with citation, no?

73,

Frank
K4FMH
ARRL Asst Director, Delta Division
Editor-in-Chief, Springer (ret.)
Professor Emeritus, Mississippi State University
Re: NanoVNA connected to Amazon Fire tablet

 

I bought the Amazon Fire Tablet August 23, 2019 --- Exactly 4 months ago...
Re: Calibration Algorithm #calibration

 

On Sat, Dec 21, 2019 at 06:55 PM, Gary O'Neil wrote:


it is the objective of calibration to normalize the measured standards to
those boundaries.
Hi Gary,

Actually, it is the objective of calibration to normalize the measured standards to their imperfect definitions, not to the ideal boundaries.

For example, let's say the actual short standard has a Gamma of -0.99 + j0.01. After calibration, if that short is then attached to the VNA's port, the VNA should display -0.99+j0.01 as its Gamma.

And if this is the result that the new algorithm would generate, great! But if the new equation normalizes it to -1,0, there's a problem.

One of the beauties of the traditional one-port, 3-term error model is that the three standards used for calibration could be anything and do not need to be S.O.L. -- as long as you know the Gammas of the standards, you can use these "actual" Gammas, plus their three measured Gammas, to error-correct your "Device Under Test" measurements.

In other words, if you substitute the equations for e00, e11, and delta_e into the traditional equation Gamma(DUT,actual) = (Gamma(DUT,measured - e00)/(Gamma(DUT,measured)*e11 - delta_e), you will get a single function in terms of 7 parameters. I.e:

Gamma(DUT, actual) = function(Gamma(DUT, measured), Gamma(S1, measured), Gamma(S2, measured), Gamma(S3, measured), Gamma(S1, actual), Gamma(S2, actual), Gamma(S3, actual), where S1, S2, and S3 are the three calibration standards.

But this is a very messy equation, and usually its calculation is broken up into several steps, i.e. the separate calculation of e00, e11, and delta_e, as e00 and e11 are also used in the 12-term 2-port correction. But, if just doing 1-port S11 measurements, there's no reason why Gamma(DUT,actual) can't be expressed, and solved, as a single equation of seven parameters.

If the new equation is also a function of the same seven parameters, but if it looks different from the traditional equation "expanded out", then it should be possible, through equation manipulation, to show that the two are equivalent. If this cannot be done, then I would suspect an error or incorrect assumption.

Anyway, this is not to say that the new equation is not correct, but I'm personally hesitant to declare it "finished" until I see more information.

- Jeff, k6jca
Re: errors of "error" models

 

#91: Elevating a [NanoVNA] System to an Instrument of Laboratory Level

Hello,

Allow us, please, to declare that our research efforts here have to do with our
curiosity regarding the investigation of the possibilities to certify the use of a
[NanoVNA] System as an Instrument of Laboratory Level.

Such a Cause is attainable not only through a serious comparison of it with
existing [LabVNA]s but, much more than that, by the careful and reliable
estimation of the Uncertainty Core of its measurements.

And as you may see, from our thoughtful route in this thread until now, this is
a time consuming process successively rewarding step-by-step The Common
Users like us.

Sincerely,

gin&pez@arg

:#91
Re: QEX Magazine #tutorials

 

Thank you for that link Herb,

I am an (foreign) ARRL member and also read QEX (wonderful magazine). I lost a QEX-article that I particularly find interesting and now found it back again in the archive.

73,
Arie PA3A

Op 22-12-2019 om 01:06 --? hwalker:

Dr. Steber is one of my favorite authors. He has published easy to follow articles on DIY VNA's and other instruments in QEX magazine and Nuts and Volts magazines over the years. Pretty much all those articles are available for download on the web. Its usually just a matter of waiting for some time after the initial magazine is published before selected articles start to appear.

Entire QEX magazine archives from 1982-2016 have been available at for some years now.

I don't have a subscription to QEX but if there is content that interests me I do purchase individual issues as a way of supporting the author and encouraging him to publish future articles.

- Herb
Re: Looking for firmware with battery indica

 

Did you download from the github repo at:.??


Its a zip'ed file. Everything you need is inside the file and you need to extract what you want and yes, the dfu filen is there.?
Use 7zip or the windows built-in unzip utility.?


On Sun, 22 Dec 2019 at 6:28 AM, nanovnauser@...<nanovnauser@...> wrote: ive downloaded the reald firmware but there is no hex or dfu file??
Re: Choke Series resonant frequency measurement

 

To find a series resonance you are looking for the frequency where the impedance is a minimum.
All three techniques you suggest will work.
1. Series between two ports, look for the frequency of maximum S21
2. Shunt, you only need 1 port. Look for the frequency of a dip in S11. Don't connect Port 2
3. With two coupling coils the result will be like #1, The frequency for maximum S21 is the self resonance
4. With one coupling loop the series resonance will be the minimum in S11, like #2. This is pretty much what you are doing with the grid dip meter, looking for maximum energy absorption,

Try all of these techniques to see the difference. That's one of the great thing about the nanoVNA it's a great educational tool at an affordable price.

73 de K9GXC, Jim
Re: Looking for firmware with battery indicator, 1500 and big font

 

ive downloaded the reald firmware but there is no hex or dfu file??
Re: NanoVNA-Saver 0.2.0

 

Hi, Rune!
I have read your conversation with Bryan WA5VAH about TDR. As I understood, there is a problem with putting the device in TDR Transform mode and back in NanoVNA Saver.
Yesterday I have made measurements of impedance of some coax cables, using NanoVNA built-in TDR. Meniu item - TRANSFORM/LOW PASS STEP. The results were amazing. I supposed that it would be very interesting to see all this pictures on PC screen and to have an abbility to save the results on PC. So, if there is a problem with switching to TDR, maybe it is possible to write some kind of GUI esepecially for TDR measurements? It will be very usefull!
Thanks and 73!
Andy, UA3RAW
Re: QEX Magazine #tutorials.

 

This is where radio clubs are handy. I am really surprised at the hidden technical level of some of my club members. They don¡¯t wear a badge or sign showing their skill level. They might even subscribe to QEX. I am sure if club members would ask my club would get a subscription. So, ask around. There may be someone in your club who subscribes to QEX and will loan you his or her copy. I bring year old QSTs and CQ to the club room and throw them on a bench for others to take and read. Or if you have the issue in question donate it to Paul W0RW¡¯s radio lending library. Then others can check it out via mail and enjoy it, even make a copy of the article for their own use. All perfectly legal.

Paul¡¯s lending library. Check it out.

Another thought (flame suit on) How many of us frivolously spend the equivalent of an ARRL membership each year, even on specialty coffee or some other snack treat? I dare to say our bands are worth a lot of money to commercial interests and who else is out there protecting our interests? No ARRL? No frequencies! No hobby! There, I said it.

Dave K8WPE. An ARRL member for 60 years. Even saved my nickels and dimes back in 1960 to be a member.

David J. Wilcox K8WPE¡¯s iPad

On Dec 22, 2019, at 4:59 AM, Philip Stevens <philg3ses@...> wrote:

?It is a pity there are one or two members of the "something for nothing"
set on this forum.
If Dr.Steber wishes to publish his findings in QEX, where he is financially
rewarded, then that is his choice.
Writing technical articles takes considerable time and effort as I know
from personal experience as a contributor to Sprat, the magazine of the
GQRP Club. I receive no remuneration from the GQRP Club and I am happy with
that.
I have been a member of the ARRL for 43 years but cannot afford the extra
cost of QEX. This I accept.
Many years ago, as a postgraduate university student, I wrote a large
dissertation on the development of early radio receivers. The thesis, which
took considerable time and effort, is the property of the university and
myself.
Thank you to all who have freely given their time and energy to the design
and development of the NanoVNA.

Phil G3SES

On Sun, 22 Dec 2019 at 01:24, Dave Daniel <kc0wjn@...> wrote:

Hmmm. That is indeed interesting.

DaveD

Sent from a small flat thingy

On Dec 21, 2019, at 19:05, W5DXP <w5dxp@...> wrote:

From: Dave Daniel: Define ¡°common knowledge¡±.
I would say anything that can be obtained from simply surfing the web.
Re: QEX Magazine #tutorials

 

It is a pity there are one or two members of the "something for nothing"
set on this forum.
If Dr.Steber wishes to publish his findings in QEX, where he is financially
rewarded, then that is his choice.
Writing technical articles takes considerable time and effort as I know
from personal experience as a contributor to Sprat, the magazine of the
GQRP Club. I receive no remuneration from the GQRP Club and I am happy with
that.
I have been a member of the ARRL for 43 years but cannot afford the extra
cost of QEX. This I accept.
Many years ago, as a postgraduate university student, I wrote a large
dissertation on the development of early radio receivers. The thesis, which
took considerable time and effort, is the property of the university and
myself.
Thank you to all who have freely given their time and energy to the design
and development of the NanoVNA.

Phil G3SES

On Sun, 22 Dec 2019 at 01:24, Dave Daniel <kc0wjn@...> wrote:

Hmmm. That is indeed interesting.

DaveD

Sent from a small flat thingy

On Dec 21, 2019, at 19:05, W5DXP <w5dxp@...> wrote:

From: Dave Daniel: Define ¡°common knowledge¡±.
I would say anything that can be obtained from simply surfing the web.
Choke Series resonant frequency measurement

 

How does one measure the series resonant frequency of a RF plate choke using a nannovna.

1. Do you put the choke in series between the 2 ports
2. Do you place the choke in parralel to the 2 ports
3. Do you use it as a dip meter with 2 x loose coupling coils on a shorted chokes.

When I used a dip meter i used to short the choke out and couple the dip meter to end of the choke

Thanks
Re: Calibration Algorithm #calibration

 

On Sat, Dec 21, 2019 at 07:14 PM, Gary O'Neil wrote:


The important significance of this new algorithm is that it entirely mitigates
the need for an independent multi-term calibration process and/or algorithm.
Gary, I'm do not understand this.
The new formula has been proven to be identical to the well known calibration formula so it seems to be a single formula to describe G=f(g,s,l,o,S,L,O) instead of the formula using G=f(g,a,b,c) where a,b,c are defined using 3 different f(S,L,O,s,l,o)
The advantage of the new formula seems it is elegant. The disadvantage is the computational effort to use it.
Or am I again making a big mistake?


--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK
Re: Screen replacement?

 

I had the same problem.

Then the replacement screen arrived smashed to pieces.

These idiots have no idea how to pack things for safe transport so hammer it into them when you buy one that it must be packed properly.

One other thing to watch - some displays have the ribbon connector for the touch screen on the wrong side.

I've decided not to bother replacing the screen on mine and will just use it with a computer.

--
Terry VK5TM
( )
Re: errors of "error" models

 

#90: On the -Second- Arithmetical Method of Error Estimations in
VNA Measurements
-
REFERENCE:
ann : next-to-come : a practical introduction to errors of "errors"
20 December 2019 - /g/nanovna-users/message/8436

Hello,

Allow us, please, to inform you that after our presentation of
our -First- Analytical Method of VNA Error Estimations Using
Complex Differential Error Regions DERs and Real Differential
Error Intervals DEIs,

- - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - -

we are just starting our step-by-step presentation of our
-Second- Arithmetical Method of Error Estimations in VNA
Measurements Using Complex Arithmetical Error Regions AERs and
Real Arithmetical Error Intervals AEIs, as they introduced by us
in:

"Measurement Uncertainty in Network Analyzers: Differential
Error Analysis of Error Models - Part 1: Full One-Port
Calibration", FunkTechnikPlus # Journal, Issue 1, Thursday 31
October 2013, p. v4-18, Fig.1 page 20:




[1] excerpt of ftpj:


"Total Differential Errors in One-Port Network Analyzer
Measurements with Application to Antenna Impedance",
Radioengineering, Vol. 16, No. 2, June 2007, p.7, Fig. 7 and
Fig.10:




[2] excerpt of re:


- - - - -

#90.00 : A Practical Introduction to our -Second- Arithmetical
Method of Error Estimations in VNA Measurements : [SAMEEVNAM]

In addition to [1] and [2] above, we also just uploaded our
first SAMoEEiVNAM program, as well as and its results, at:



regrading our [NanoVNA] operation at ~405 MHz, as follows:

[3] Our Maxima Program SAM.20191222.MC:


[4] Its Numerical Results:


[5] A graphical Error Value result of Real Part Rt of Zt withinin its R-DEI:


[6] A graphical Error Value result of Imaginary Part Xt of Zt within its X-DEI:


[7] A graphical Error Value Zt within its Z-DER:


Notably, this SAMoEEiVNAM is most appropriate for Programming.

- - - end : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - - - - -

Sincerely,

gin&pez@arg

:#90.00
Re: Calibration Algorithm #calibration

 

Hi again Jeff;

Don't you just love it when your comments get posted before you are finished drafting it? :-)

I had only one final comment in my response to you on this...

The important significance of this new algorithm is that it entirely mitigates the need for an independent multi-term calibration process and/or algorithm. The accuracy of the corrected result is determined precisely by the defined accuracy of the standards used. The standards corrections, and measurement uncertainties are embedded and included in every measurement, and utilized by the algorithm to compute the corrected result.

--
73

Gary, N3GO
Re: Calibration Algorithm #calibration

 

Hi Jeff;

I agree that the proof is certainly terse as you say. Likely an additional and serendipitous artifact of the elegance of the approach. :-)

The use of ideal -1, 0, and +1 standards in the proof simply serve to define them as ideal. Keep in mind also that all variables are complex values; hence the ideal standards all have imaginary components of zero. While these values can, and in many, if not most, cases will be defined as ideal in practice, it is the objective of calibration to normalize the measured standards to those boundaries. They are and will be set to the value and accuracy defined by the user based on their knowledge of the test standards used in their application, and the accuracy to which they wish to have them defined whether through published manufacturing tolerance specifications, or through elaborate laboratory characterization and comparison to certified industry reference standards.

The defined or "given" values as well as the computed result are upper case, and all lower case variables represent raw data measurements, with G being equal to the corrected reflection coefficient of a DUT exhibiting a measured reflection coefficient of g.

t



--
73

Gary, N3GO
Re: Screen replacement?

Bob Albert
 

I don't think that has touch capability.Bob

On Saturday, December 21, 2019, 03:00:59 PM PST, <nanovnauser@...> wrote:

try this,its biggfer but will work:
Re: QEX Magazine #tutorials

 

Hmmm. That is indeed interesting.

DaveD

Sent from a small flat thingy

On Dec 21, 2019, at 19:05, W5DXP <w5dxp@...> wrote:

From: Dave Daniel: Define ¡°common knowledge¡±.
I would say anything that can be obtained from simply surfing the web.
31301 - 31320 of 39696