2port measurement determining Zdut with S11 and S21
Hello Roger,
I thought that the method I used now for the resistors was working. And it
seems to work at least for these 4 resistors (330, 985, 5160 and 21800);-)
But I now did a 1:1 Guanella choke as dut and it seems to behave
differently in a 2 port measurement...
Here are the 2 port measurements NanoVNA Saver of my 1:1 Guanella choke (I
also attached the 11Guanella-corebraid-1s21.s2p file):
[image: afbeelding.png]
As you can see the S21 R+jX has totally different form (e.g. peaks) than
S11 R+jX.
If I use the formula of (Page
10) :
[image: afbeelding.png]
I can determine with the 2 port measurements Zdut (Zx) in two ways through
S11 and S21 2 port measurement.
Z2pseries(S11)=(Zsource+Zload)*S11/(1-S11)
Z2pseries(S21)=(Zource+Zload)*(1-S21)/S21
[image: afbeelding.png]The green curve should be close to the red (blue
dotted or orange dotted) ones (as when using my method for the resistors),
but with the choke they are totally different. I must be doing something
(obviously?) wrong! But what? Any help is welcome.
All the best,
Victor
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Re: #firmware NanoVNA SAA-2N firmware not loading
#firmware
Follow up - the new firmware I uploaded was the wrong one, and I cannot get to a dfu mode either by -QT, the screen menus or by toggling the left jog and switching on and off. I went thru all the menu items and can't find any way to change the firmware. I did find a button for "Dump firmware" as follows: Config>Expert Settings>More>Dump Firmware . But tapping this button opens a number/alphabet entry page and the word bin in a white bar at bottom. I'm lost in the forest again. Again, the firmware build date is Apr 3, 2022, and -QT doesn't see the device.
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72/73 de k1qed, ?bob.c ? ? ? ? qrp 4evr!
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Thank you Igor and Dislord.
I just acquired a new NanoVNA H4, after using my original NanoVNA H for the last several years.
With all features of the H4 over the H model, it is like starting all over again.
I was wondering what the save function was really doing.
Both of you now answered it.
I thank those who keep updating and improving the NanoVNAs.
Thank you again,
Clyde Lambert KC7BJE
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Re: #firmware NanoVNA SAA-2N firmware not loading
#firmware
Hi Tim, brevity did the trick, I was able to get back to life using the left jog and on-off switch. The SAA-2N showed up on the -QT software (on my MacBookPro) and got the prompt to load software. Went ahead, but not sure now which download I loaded.... On the Version screen I see NanoVNA-V2-firmware and a build time of 4/3/22, 13:30:34.
Thks for your encouragement, but now I hope I got the right firmware, I hope it is not too new for a two or three year old SAA-2N. Now let's see what happens!
72/73 de k1qed, bob.c qrp 4evr!
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I guess I need to express my gratitude for allowing me to ACCESS the forum, again.
I am still looking for any text form of "menu" symbols AKA "menu dictionary".
( No, I do not desire to be "part of solution" have few "honey does" of higher priority. )
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Still OK Neil
Colin MM5AGM
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Wow, touchy, ta, ta.
Mike C.
PS I didn't know engines had ears!!
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Show quoted text
On 6/8/2022 7:32 PM, Anne Ranch wrote: Let me restate - I have been actively using nanoVNA for about two weeks -
and I am a certified engineer and real engineers do not read manuals...
Consequently I make mistakes , because I only read
what I IMMEDIATELY need...
With that said - I find the wast variety of "menu flowcharts " .
disgusting.
It looks as the primary goal was to cram everything in minimal space...
What happen to real (IBM) style flowcharts ?
GUI ( graphical USER interface ) Pitiful.
Any nanoVNA " coders " ever hear about "tool tips " ?
How about " document header(s) " levels?
In my years of gainful employment I did "(graphical) user experience " quality control...
(some "coders" did not like me ...)
and if anybody is going to say " what do you expect for free ..."
I AM DONE HERE
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Re: #firmware NanoVNA SAA-2N firmware not loading
#firmware
DFU mode does nothing with the screen . . . Perform the steps to enter it (DFU mode) on your unit, and see if it shows up on USB.
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On June 9, 2022 8:39:24 PM CDT, Robert Coleman <rcoleman@...> wrote: Hi Tim, I would like to get to any mode, but the device does not respond to any input, button or tap. The screen is white and nothing gets a reaction. bob.c
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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Re: #firmware NanoVNA SAA-2N firmware not loading
#firmware
Hi Tim, I would like to get to any mode, but the device does not respond to any input, button or tap. The screen is white and nothing gets a reaction. bob.c
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On Thu, Jun 9, 2022 at 03:17 PM, Fred Moore wrote:
Just out of curiosity, is the processor type listed on a display rather
than opening up the unit and looking at the chip?
Yes it is listed under Platform after you enter Config-Version. What I don't know if that is the actual chip on the board or what the developer of the firmware just entered as default text for that field. Perhaps DiSlord can comment since he created that display page.. Roger
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Just out of curiosity, is the processor type listed on a display rather than opening up the unit and looking at the chip? On Thu, Jun 9, 2022 at 5:15 PM Roger Need via groups.io <sailtamarack= [email protected]> wrote: According to Hugen (manufacturer of -H4) the latest firmware can run on a
STM32F302CCT6.
/g/nanovna-users/message/24748
Comparison chart >>
Roger
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measuring T equivalent circuit of an antenna
Hello all of you,
I was wondering if someone measured the T equivalent circuit of an antenna?
So the antenna is seen as having three ports: two going to the two points
of say a dipole and the third port going to the Earth.
G3TXQ is using such a T equivalent circuit in his article (but no values):
(Drawing 2).
There is an article that described the derivation of these three
impedances:
I did this for my 40m OCFD antenna anc a 200 *¦¸* load on a balun and a
transmission line. I got these results:
I was wondering if other people did similar and have got some
(similar/different) results to share. I am not sure if I indeed measure the
correct thing...
*Advice or feedback on these measurements are welcome?** Thanks.*
*All the best,*
*Victor*
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Re: How to make nanoVNA "bulletproof" ?
Sigi,
My cupboard yielded exactly 1 suitable box but, in the event, having a bigger format gets away from the "little and fiddly" form of the nano, as well as accommodating the nice R&S flex patch cables I found.
Yes, by all means select the bulkhead adapters according to need. With a bit of Dremel work I think I could have included a third set of connectors but there was no need in my application.
Doug: re pictures: I see a thumbnail with my first post. Click for a larger image.
73, Peter.
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Re: How to make nanoVNA "bulletproof" ?
A photo please.
Doug
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On 09/06/2022 09:26, K8HTB wrote: I cut a piece of 1/4 inch plexiglass about 9 inches x 6 put Velcro on the nanovna and cables . It keeps the cables from damaging the connectors. De K8HTB
-- */If you forward this email, please delete the forwarding history which also includes my email address. When sending emails, please BCC so as to hide all addresses. Thanks for helping to prevent Scammers and Spammers from mining addresses and spreading viruses./ Doug Kearney * *Ottawa, ON *
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This email has been checked for viruses by Avast antivirus software.
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Hi Colin, is your NanoVNA still working okay?
I ask because the one i have (bought off ebay a while ago i think) has now got lines all over the screen and is barely readable.
Thanks
Neil
M7SVH
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Re: How to make nanoVNA "bulletproof" ?
Nice job.... But i would bot use pl sockets but n sockets cause with v2 plus4 or saa2n i measure also on 13cm...
Even at 70cm the n socket is better as pl...
Your case is so big it should be easy to add a bigger sized battery... Grin
Greetz
Dg9bfc sigi
Am 09.06.2022 16:54 schrieb Siegfried.Jackstien@...:
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Show quoted text
Add sma to n adaptors...can or better should be with flange (others with
big nut may work also) ... Screw flange on a sheet metal angled 90 degrees
to form end and base plate...
And then use thicker cables with n connectors like i also use on my saa2n
.... Ok you then need new calibration set with n connectors.. But that all
will be more robust as using those flimsy sma..
If you stay on sma then i recommend to use sma extender (male female
adaptor).... So if worn out you can replace that extender
Both will make it more robust...
Either n sockets....
Or sma extender... So if worn out... Easy to replace
I prefer n socket in most cases... But i have both cause i own an saa2n
and a v2plus4... Both with modded fw from dislord :-)
Dg9bfc sigi
Am 09.06.2022 15:30 schrieb Anne Ranch <anneranch2442@...>:
Excellent idea - combine "rotator plate" ( for stability ) with superglue
and Velcro !
I actually was not looking to? buy those tiny screws to permanently mount
the device onto the plate ...
Vaclav AA7EJ
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Re: How to make nanoVNA "bulletproof" ?
Add sma to n adaptors...can or better should be with flange (others with big nut may work also) ... Screw flange on a sheet metal angled 90 degrees to form end and base plate... And then use thicker cables with n connectors like i also use on my saa2n .... Ok you then need new calibration set with n connectors.. But that all will be more robust as using those flimsy sma.. If you stay on sma then i recommend to use sma extender (male female adaptor).... So if worn out you can replace that extender Both will make it more robust... Either n sockets.... Or sma extender... So if worn out... Easy to replace I prefer n socket in most cases... But i have both cause i own an saa2n and a v2plus4... Both with modded fw from dislord :-) Dg9bfc sigi Am 09.06.2022 15:30 schrieb Anne Ranch <anneranch2442@...>:
Excellent idea - combine "rotator plate" ( for stability ) with superglue
and Velcro !
I actually was not looking to? buy those tiny screws to permanently mount
the device onto the plate ...
Vaclav AA7EJ
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Re: How to make nanoVNA "bulletproof" ?
Anne,
I realize this is a bit different to the approach you're thinking about but maybe it's of some interest. I "re-packaged" my nanoVNA-F to address some of the issues you mention, and to provide some "saver" connectors. Although the nanoVNA is essentially a disposable item I decided to give it the best chance possible at a long and consistent measurement life; I've attached a picture to show the general idea.
The plastic instrument box is spare from another project and I hinged the lid using hardware store small cabinet hinges. The VNA is mounted using velcro and the bulkhead adapters and patch leads came from the junk box or eBay. I often use the unit in the field with a laptop, most recently for some LF/MF antenna work. Although probably unnecessary in the portable setup I did, as a matter of practice, include a small toroid choke (type 77 material) for the USB lead. Finally, I couldn't function without a decent stylus when using the VNA stand-alone.
All of my external systems under test have PL259 or SMA connectors, hence the choice of bulkhead adapters.
Best regards,
Peter.
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Re: How to make nanoVNA "bulletproof" ?
Excellent idea - combine "rotator plate" ( for stability ) with superglue and Velcro !
I actually was not looking to buy those tiny screws to permanently mount the device onto the plate ...
Vaclav AA7EJ
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Clyde Lambert
Colin Campbell
Mike C.
Roger Need
Peter Hall, VK6HP/VK6MJM
