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Saw this the other day on Instructables — note that it talks about NanoVNA, etc. Seems like this could be adapted with some code changes to a general purpose auto antenna tuner:

On Jul 9, 2021, at 7:10 AM, W4MTM Dale Beach via groups.io <banjo102@...> wrote:

Rig runner makes a circuit board that can be used for building your own tuner or other projects that require an analyzer. It's called "RigExpert Antenna Analyzers AA-30ZERO". This might be what you are looking for. Attached is a picture of the unit.






<2021-07-09 06_05_50-RigExpert AA-30ZERO RigExpert Antenna Analyzers _ DX Engineering ??? Mozilla Firef.jpg>

Daniel Brown
daniel.h.brown@...

On 7/9/21 6:22 AM, WB2UAQ wrote:

To get a good idea how antennas behave check out 4NEC2 an antenna modeling program. It can be downloaded from the net free. There are other programs as well like EZNEC that might be easier to start with. Start with a dipole that has been already designed and change the parameters to see how the radiation pattern, the feed point impedance and other characteristics change.
It is well worth the time to learn how to use a basic antenna modeling program and use it conjunction with the Nanovna. Antennas can be scaled down to make them easy to support and modify.
I have made antennas for 200 MHz or higher to make them compact. In one case I just taped it to a large piece of cardboard. With the Nanovna you can use it to drive the antenna with ch0 and monitor the radiation from it with ch1 using a small sniffing antenna. The sniffer can give you an idea of the pattern and polarization. Years ago I wanted to prove that a half square antenna actually was a vertical polarization radiator with its horizontal half wave of wire connecting the two verticals. In the far field it was perfectly vertically polarized. I also did the same with a discone and learned that it does have a polarization tilt at some frequencies (old radio shack version tested at 2 meters).

Copper foil tape on paper !

I recently started a thread about using the NanoVna on 75 ohm TV antennas. I haven't found any success with a simple 50 ohm and 100 ohm resistor.
I Have tried just a connector adapter and a 50 to 75 ohm matching pad. I go thru a calibration with a 75 ohm resistor, then install either a 50 ohm load or a 100 ohm load.
Both measure about 30% low. What am I missing?
I know there is software to use with a laptop to display and manipulate the results from the NanoVna.
Is there any software that will recalculate and adjust the data to a 75 ohm system? Or can the be made?
Mikek
P.S.
All the videos I watch about this always put a filter on the NanoVna so I can't tell what it's doing. Is there a video where someone just puts on resistive loads and shows the result?

To get a good idea how antennas behave check out 4NEC2 an antenna modeling program. It can be downloaded from the net free. There are other programs as well like EZNEC that might be easier to start with. Start with a dipole that has been already designed and change the parameters to see how the radiation pattern, the feed point impedance and other characteristics change.
It is well worth the time to learn how to use a basic antenna modeling program and use it conjunction with the Nanovna. Antennas can be scaled down to make them easy to support and modify.
I have made antennas for 200 MHz or higher to make them compact. In one case I just taped it to a large piece of cardboard. With the Nanovna you can use it to drive the antenna with ch0 and monitor the radiation from it with ch1 using a small sniffing antenna. The sniffer can give you an idea of the pattern and polarization. Years ago I wanted to prove that a half square antenna actually was a vertical polarization radiator with its horizontal half wave of wire connecting the two verticals. In the far field it was perfectly vertically polarized. I also did the same with a discone and learned that it does have a polarization tilt at some frequencies (old radio shack version tested at 2 meters).

I'm not explaining this well.

Goal: understand more about how an antenna works using a Nano VNA tool in S11 mode
Translation: understand the graphs of R, X and Z vs. frequency that I get with Nano VNA SAVER
Also: understand what the S11 PHASE graph is revealing about resonance and reactance.
Finally: see that the Smith Chart in S11 mode tells me just about everything I need to know - if I can interpret the meaning of the graphs. I am always using 50 ohm coax feed line and dipole-like antennas.

So to help me understand these graphs on a real antenna, I put together a simple RLC circuit board.
I used parts from an old MFJ tuner: 200 pf air variable cap, 10 microHenry tapped coil, and a few different resistors (10 ohm to 100 ohm).

What I forgot: the S21 port is already terminated with a 50 ohm resistor.
I realized that later when my Smith Chart missed the "bull's eye" ..... rookie error.

So I can manipulate the R and L and C of my breadboard circuit and play with how changing these components (in series for now) changes the Smith Chart, the R and X graphs and the Z graph and more importantly, the PHASE graph.

Once again, a Nano VNA rookie playing and learning as I go.

The Nano VNA is just a gadget that probes my understanding of all of these cocepts.
Yes, it does not do calculus.
Perhaps WHY an antenna radiates is a bit too broad a question - for now.

But it is like trying to read my EKG to tell me how my heart is behaving.
Actuallly I think I can read an EKG with better accuracy than read my antenna's performance.

TU
De k3eui barry

Rig runner makes a circuit board that can be used for building your own tuner or other projects that require an analyzer. It's called "RigExpert Antenna Analyzers AA-30ZERO". This might be what you are looking for. Attached is a picture of the unit.

On Thu, Jul 8, 2021 at 11:53 PM, Anne Ranch wrote:

And I have I found two pins marked

SWDIO and SWCLK

Any guess what they are ?

Perhaps non customery designation for "2 wire I/O " - data and clock ?
I do not see any such signals on schematic.

SWDIO and SWCLK are the standard designations for the GPIO pins on STM devices. You seriously need to read up on these devices first.

On Thu, Jul 8, 2021 at 05:29 PM, Anne Ranch wrote:

OK, I am too lazy to use commands to get "nanoVNA-saver" running.

Anybody tried the attached procedure to run it as "standard" Linux / Ubuntu
application ?
Little long but seems accurate.

The tutorial describes how you can write your own python program, I suspect you do not want this.
The easy way:
- Download the zip from github

- unpack this into a directory (e.g. /home/anne/projects/nanovna-saver)
- open a terminal window, go to this directory (type cd /home/anne/projects/nanovna-saver)
- do what is told in this lengthy tutorial in step 11:
Step 11: Now to run your Python file, all you have to command is ‘python nanovna-saver.py’.

This is the last version (3.4) of the original NanoVNA-H with the 2.8 inch display.?
/g/nanovna-users/photo/0/34671.21928.0?p=Created,,,20,2,100,0
Folks - browse the forum's Photo section!? There is just as much info there as in the message area.?



On Thu., 8 Jul. 2021 at 9:11 p.m., Jim Lux<jim@...> wrote: On 7/8/21 6:07 PM, Larry Rothman wrote:

Anne, please browse the forum's Wiki.
There is alot of info there including the schematics for each revision of nanovna, H and H4.
There also photos of various boards.

ANd if you post a photo, someone might be able to ID it for you.

?
?
? ? On Thu., 8 Jul. 2021 at 6:53 p.m., Anne Ranch<anneranch2442@...> wrote:? I got brave and removed the cover.
Now I am looking? at PCB with absolutely no identification.

Unauthorized clone or somebody not interested to advertise their work ?

Opened the "git" link and was looking for schematic...
That got me to another "git" site and the only thing I can identify for sure is the
STM32 processor....

I am not sure I should go? to the "trouble" to post? PCB picture here.

For now l? am interested now to "hook up " bluetooth module to my hardware,
if that is even an option.

So I was looking for anything resembling input / output.

And I have I found two pins marked

SWDIO and SWCLK

Any guess what they are ?

Perhaps non customery? designation for "2 wire I/O " - data and clock ?
I do not see any such signals on schematic.

On 7/8/21 6:07 PM, Larry Rothman wrote:

Anne, please browse the forum's Wiki.
There is alot of info there including the schematics for each revision of nanovna, H and H4.
There also photos of various boards.

ANd if you post a photo, someone might be able to ID it for you.

On Thu., 8 Jul. 2021 at 6:53 p.m., Anne Ranch<anneranch2442@...> wrote: I got brave and removed the cover.
Now I am looking? at PCB with absolutely no identification.

Unauthorized clone or somebody not interested to advertise their work ?

Opened the "git" link and was looking for schematic...
That got me to another "git" site and the only thing I can identify for sure is the
STM32 processor....

I am not sure I should go? to the "trouble" to post? PCB picture here.

For now l? am interested now to "hook up " bluetooth module to my hardware,
if that is even an option.

So I was looking for anything resembling input / output.

And I have I found two pins marked

SWDIO and SWCLK

Any guess what they are ?

Perhaps non customery? designation for "2 wire I/O " - data and clock ?
I do not see any such signals on schematic.

Anne, please browse the forum's Wiki.?
There is alot of info there including the schematics for each revision of nanovna, H and H4.?
There also photos of various boards.?


On Thu., 8 Jul. 2021 at 6:53 p.m., Anne Ranch<anneranch2442@...> wrote: I got brave and removed the cover.
Now I am looking? at PCB with absolutely no identification.

Unauthorized clone or somebody not interested to advertise their work ?

Opened the "git" link and was looking for schematic...
That got me to another "git" site and the only thing I can identify for sure is the
STM32 processor....

I am not sure I should go? to the "trouble" to post? PCB picture here.

For now l? am interested now to "hook up " bluetooth module to my hardware,
if that is even an option.

So I was looking for anything resembling input / output.

And I have I found two pins marked

SWDIO and SWCLK

Any guess what they are ?

Perhaps non customery? designation for "2 wire I/O " - data and clock ?
I do not see any such signals on schematic.

Those are the debug pins. Look elsewhere for the UART port if you have one. May only be available on H4 version.
Gary
W9TD

I got brave and removed the cover.
Now I am looking at PCB with absolutely no identification.

Unauthorized clone or somebody not interested to advertise their work ?

Opened the "git" link and was looking for schematic...
That got me to another "git" site and the only thing I can identify for sure is the
STM32 processor....

I am not sure I should go to the "trouble" to post PCB picture here.

For now l am interested now to "hook up " bluetooth module to my hardware,
if that is even an option.

So I was looking for anything resembling input / output.

And I have I found two pins marked

SWDIO and SWCLK

Any guess what they are ?

Perhaps non customery designation for "2 wire I/O " - data and clock ?
I do not see any such signals on schematic.

Use the touch command to create a new document.

On Thu, Jul 8, 2021 at 11:29 AM Anne Ranch <anneranch2442@...> wrote:

OK, I am too lazy to use commands to get "nanoVNA-saver" running.

Anybody tried the attached procedure to run it as "standard" Linux /
Ubuntu application ?
Little long but seems accurate.








--

*Marshall Harrison, *
*Microsoft rMVP
<>*
*904.655.6502*

Well, as always judged the source too soon
in very few steps it asks to "create new document "
unfortunately the folder has no clue what "document " is - there is
no option to create document.

SimSmith:

Excellent Tutorial:
<>

Dave - W?LEV

--
*Dave - W?LEV*
*Just Let Darwin Work*

OK, I am too lazy to use commands to get "nanoVNA-saver" running.

Anybody tried the attached procedure to run it as "standard" Linux / Ubuntu application ?
Little long but seems accurate.

Use SimSmith.

Anne,

Actually, I'm more interested in determining the matching range of a tuner with various antennas.

I've used the AI1H method** of testing various tuners but that's a static resistance method. With some of my Z-Match tuners the range would seem to be from about 3 to 3k Ohms. But what would it be with an actual complex impedance (conjugate match). The nanoVNA measurement options could provide that info, I think...?

**Frank Witt, AI1H, Articles in QST Apr/May ‘95, Antenna Compendium vol 5, QEX (Sep/Oct ‘03),

--
Chuck, W5USJ

Nice topics Barry

just one small (nitpicking) remark on the wording in
3) Why does every feed line have an SWR of some value at some frequency?

Actually it's not the feedline that has an SWR 'of some value'.
The line has a characteristic impedance (see item 2) )
It's the (mismatched) load that is transformed into something else along the line, causing the SWR.

Also a fun topic : how can a capacitive load suddenly be measured as some inductive impedance elsewhere along the line ? ... call our friend Smith to help.

73,
Luc ON7DQ