开云体育

try this,its biggfer but will work:

I don't have the information you seek; however there is a larger version of the nano selling for around $150.? You might consider this as an opportunity to get a larger screen.? The original is painfully small.? In some cases I find need to use a magnifying glass.
Compounding this is the fact that young engineers don't seem to have a grasp of hardware and those who do aren't young (such as myself) and so have vision issues.
Perhaps you can locate a donor unit that has failed in some other way.
Bob K6DDX

My VNA arrived with a busted screen, very bad packaging, unit works when connected to my computer.
I received a full refund from Amazon despite what the vendor wanted which was a 40% refund..
I would like to replace the screen but can't find a model or part number for it.
As suggestions would be greatly appreciated.
Thanks for the help!

But that does not include wide re-publication .

DaveD

Sent from a small flat thingy

It is allowed as "Fair Use".



"In its most general sense, a fair use is any copying of copyrighted material done for a limited and “transformative” purpose" (fair use of the first sentence of the above web page).

73

-Jim
NU0C


On Sat, 21 Dec 2019 21:07:00 +0000 (UTC)
"Bob Albert via Groups.Io" <bob91343@...> wrote:

Quoting is always at the discretion of the copyright holder.? Any part of a copyrighted work is protected.
Bob
On Saturday, December 21, 2019, 12:57:02 PM PST, W5DXP <w5dxp@...> wrote:

Isn't it OK to quote copyrighted articles as long as one credits the source? How about just quoting the parts that are not already common knowledge?

Quoting is always at the discretion of the copyright holder.? Any part of a copyrighted work is protected.
Bob

Define “common knowledge”.

DaveD

Sent from a small flat thingy

Isn't it OK to quote copyrighted articles as long as one credits the source? How about just quoting the parts that are not already common knowledge?

Ron, of course anyone is entitled to have a copyright for his writings.? That's part of what makes the free enterprise system as good as it is.? (And it isn't always so good.)
Nobody should complain if someone wants to be paid for his efforts.? And if he decides to give it away no charge, that's his business.
I agree that it would be nice to get all this hobby related stuff without shelling out money but that's not the siruation here.? The operative word is 'hobby' and many resent someone who wants to profit from it.
The world is what it is and no one of us can change it by very much.
Bob K6DDX

Hopefully this will get fixed in Rune's next release. Are you around Rune??

@Erik, PD0EK
-
REFERENCES:
[2] 21 December 2019 - /g/nanovna-users/message/8473
[1] 10 December 2019 /g/nanovna-users/message/8105

Dear Erik,

If we understand correctly, we have to start from [1]:




and transfer * c o r r e c t l y * their equations to Maxima, as in [1]:



and/or as in [2]:

/g/nanovna-users/attachment/8473/Check.PNG

But, we think that, as it seems, there is a wrong transferring of them
regarding some signs, as well as an interchanging of small letters
with capital ones regarding the names of variables.

Would you check for us, please, these two particular points ?

Best regards,

gin&pez@arg

Hi Jeff
You are right. The S21 phase show double phase shift but Group delay is correct
Delay(ps)=(phaseshift[degree]/freq[MHz]/360)*1e6
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af Jeff Anderson
Sendt: 21. december 2019 20:21
Til: [email protected]
Emne: Re: [nanovna-users] Calibration Algorithm #calibration

On Sat, Dec 21, 2019 at 12:30 AM, <erik@...> wrote:

Look in the source code of nanoVNA-saver on github

There might be a slight error in Rune's S21 compensation.

Looking at his code, he defines the Thru's impairment as:

gammaThrough = np.exp(np.complex(0, 1) * 2 * 2 * math.pi * self.throughLength * f * -1)

I believe there should only be a single '2' in the exponent (i.e. 2pi, not 4pi) because, for the S21 measurement, the signal only travels one time through the thru. I.e. the Thru's delay is e^(-j2pi*length(sec)*F(hz)), unlike the one-port SOL standards where there is a trip from the reference plane to the actual S, O, or L, and then back again to the reference plane (and thus the -j2pi*length*F delay term is doubled).

Apart from that, I think his equations look good (although I would have chosen a different name for gammaThrough, because this is a Transmission parameter, not a Reflection parameter. But very minor nit).

Anyway -- I'm certainly no expert in the12-term correction equations. Others more knowledgeable might want to speak.

- Jeff, k6jca

Brings back (unpleasant) memories. A few years ago, I posted some information on eHam that Electric Radio Magazine had an excellent 3 part article (done by Ray, N0DMS, the Editor) concerning some effective improvements to the Hallicrafters SX-117.
I was immediately deluged my 'requests' and even a few 'demands' that I copy the articles and send them out, FREE of course.

When I told these cheapskates that the info was Copyrighted, I was called a bunch of names I wouldn't care to use here.
Yes, back issues were/are available for a very modest fee from ER Mag.

Sigh.....

ron
N4UE

On Sat, Dec 21, 2019 at 09:40 AM, Gary O'Neil wrote:

They also provided the “proof” for this in an earlier post #8013.

Hi Gary,

Well, that proof in #8013 is certainly terse!

I have a question:

From the proof, I notice that sometimes G is set equal to +1 or to -1 (for open or short) and then this equality is used to simplify the equations. But I'm wondering -- when is G ever equal to +1 or -1? Real Shorts and Opens have non-ideal Gammas, and, when these imperfections are used to define the standards (as, for example, part of a cal kit's definitions) and the VNA subsequently calibrated using these standards, the VNA's measured S11 values for these standards should map to these imperfections and not map to -1 and +1.

In other words, why set G to +1 or -1?

Thanks for any insight you can provide.

- Jeff, k6jca

On Sat, Dec 21, 2019 at 12:30 AM, <erik@...> wrote:

Look in the source code of nanoVNA-saver on github

There might be a slight error in Rune's S21 compensation.

Looking at his code, he defines the Thru's impairment as:

gammaThrough = np.exp(np.complex(0, 1) * 2 * 2 * math.pi * self.throughLength * f * -1)

I believe there should only be a single '2' in the exponent (i.e. 2pi, not 4pi) because, for the S21 measurement, the signal only travels one time through the thru. I.e. the Thru's delay is e^(-j2pi*length(sec)*F(hz)), unlike the one-port SOL standards where there is a trip from the reference plane to the actual S, O, or L, and then back again to the reference plane (and thus the -j2pi*length*F delay term is doubled).

Apart from that, I think his equations look good (although I would have chosen a different name for gammaThrough, because this is a Transmission parameter, not a Reflection parameter. But very minor nit).

Anyway -- I'm certainly no expert in the12-term correction equations. Others more knowledgeable might want to speak.

- Jeff, k6jca

On Sat, Dec 21, 2019 at 07:06 PM, <nanovnauser@...> wrote:

cant someone copy the article and save it to google drive and post a link?

Erm no Paul (M3VUV).
It's called copyright.

ARRL is like that.? They are a business and have to justify asking people to join and pay fees.
I have avoided joining ARRL for my 70 years as a ham because I always felt their pecuniary interests were more important than their stated mission.
I don't like some of their publications; I don't believe their articles are properly researched and validated.? But again, it's a business and the bottom line is the important thing.
Some of their free services are useful to me, such as the chart of the ham bands and the code practice on HF.? I own some of their publications but am very skeptical of the science.
In Indonesia, the ORARI (Organization Amateur Radio Indonesia) is the equivalent of the ARRL and I think membership is required to obtain a ham license.? But that organization sponsors many events, such as CW copying contests and hamfests and foxhunts.? They even have a uniform to wear, I think orange and white.? A vast difference from the US.
Bob

cant someone copy the article and save it to google drive and post a link??,seems pointless becoming a member as im uk and i only want to read that article,73 Paul.

You can install the Android Nanovna app on your Samsung along with TotalCommander and the use TotalCommander to copy the Nano apk from the installed apps folder to downloads. From there copy it over to your Amazon tablet and sideload it. Others on the forum have been able to sideload the apk on fire tabs without issue up to now.?



On Sat, 21 Dec 2019 at 10:17 AM, Lawrence Macionski via Groups.Io<am_fm_radio@...> wrote: When I download NanaVNA-Webapp-nightly-e20d9ae.apk from the Github.com/cho45 on my 4 month old Amazon Fire 10. using web browser "Silk" I click on the .apk and get a popup, "Do you Want to Download" I click, "OK" it gives me another popup "Done do you want to open? I click on OPEN and I get "PARSE ERROR - There was a problem parsing the package."
I downloaded the package x2 times. I also tried AKP INSTALLER app I had downloaded and used a number of times.. Same issue. Same error.

Second ITEM.. I have performed the "GOOGLE PLAY install to my Fire" at least 2 months ago, used it a number of times. No problem..? A number of posts talk about downloading "NanoVNA" from GOOGLE PLAY and it will run on the FIRE... When I go to GOOGLE PLAY I do not find any app named "NanoVNA" but find one named BLUE VNA.. and others like Metro VNA by the same author... What is very interesting is I just logged into google play using this Windoze 7 machine and I can find NanoVNA by cho45 just fine. Apparently the issue is on the FIRE. Blue VNA is written by DAn Toma- I can search on either and get it, but NanoVNA or cho45 brings me nothing.. Finally - On my Motorola moto e* plus... NanoVNA by cho45 is 1st on the list...humm.... moto e* is android 8.0.0 the Fire is Fire OS 5.6.4.0... all I can find regarding it's OS.. it was an "on sale" and a lot faster than my 4 yo Samsung.

Merry Christmas..

Consider this post NO COMPLAINT but rather REPORT OF FINDINGS...

When I use the well known formula's used for calibration (%i16) and I do a linsolve twice to get G expressed in only g,s,l,o,S,L,O and then I write out all the multiplications I get (%o20)
Factoring out your equation gives
(%o29)

As these are not the same I must be doing something wrong?????
--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK