Re: More "what clone version I have " question
OK, it is official - I own a piece on unidentifiable hardware.
It has two marked "px" pins
P1 whose labels are buried under battery plug
and P2 with addition to already mentioned pins contains pins marked
"GND" and "NRST" and something looking as "VD,,,"
After looking trhu wiri - as suggested here - I apparently , to no fault of mine ,
own " bad " or ever "more" bad clone.
And all I wanted to know if there are meas to connect directly
Bluetooth to it...
There are not , case closed.
PS I did manage to drop one of the screws, and it did not follow Murphy's law
to fall into most inaccessible place. Today is my lucky day .
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Re: That pesky 50 to 75 ohm conversion.
Try this site...
John
VE7KKQ
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On Fri, Jul 9, 2021 at 11:48 AM arnold slag <pe1owg@...> wrote: Try 2 22ohm resistors.in.serie.... 72 ohm is close to 75ohm
Op vr 9 jul. 2021 15:44 schreef Mikek <amdx@...>:
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?
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Re: That pesky 50 to 75 ohm conversion.
schreef Mikek,
Wouldn¡¯t two 22 ohm resistors in series be 44 ohms. In parallel they would be 11 ohms wouldn¡¯t they.
Larry
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On Jul 9, 2021, at 2:44 PM, arnold slag <pe1owg@...> wrote:
schreef Mikek
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Re: That pesky 50 to 75 ohm conversion.
And 2 22ohm resisters in parallel is only 11ohms ?
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On Fri, Jul 9, 2021, 14:08 AB6BT <AB6BT@...> wrote: Try 2 22ohm resistors.in.serie.... 72 ohm is close to 75ohm ??????
22+22= 44
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Re: That pesky 50 to 75 ohm conversion.
Build a 50 to 75 ohm minimum loss pad.
Search for MaximIntegrated tutorial 972 for details
Mike N2MS
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On 07/09/2021 12:48 PM Fred Moore < n40cla@... > wrote:
Good morning
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
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Re: That pesky 50 to 75 ohm conversion.
Roger that
toggle quoted message
Show quoted text
On Fri, Jul 9, 2021, 15:09 AB6BT <AB6BT@...> wrote: Try 2 22ohm resistors.in.serie.... 72 ohm is close to 75ohm ??????
22+22= 44
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Re: That pesky 50 to 75 ohm conversion.
Try 2 22ohm resistors.in.serie.... 72 ohm is close to 75ohm ??????
22+22= 44
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Re: That pesky 50 to 75 ohm conversion.
Try 2 22ohm resistors.in.serie.... 72 ohm is close to 75ohm Op vr 9 jul. 2021 15:44 schreef Mikek <amdx@...>:
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?
|
Re: That pesky 50 to 75 ohm conversion.
Good morning Mike
You need to watch this video and then calibrate your vna to 75ohms
toggle quoted message
Show quoted text
On Fri, Jul 9, 2021 at 9:44 AM Mikek <amdx@...> wrote: 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?
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Re: More "what clone version I have " question
On Fri, Jul 9, 2021 at 03:44 AM, Ronan Daly wrote:
You seriously need to read up on these devices first.
Let's be civilized and please do not tell me how serious I should be. If it is NOT OK to asks here , please say so. I am in "let's get to know nanoVNA " mode . I cannot possibly know where to start so I will ask silly questions. After looking at wiki my next step is to take the display cover off , perhaps usable I/O pins and PCB identification is there. My current concern is - not to loose the black screws. If somebody knows the size of these screws - please say so - but I can as Mrs Google , right?
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Re: That pesky 50 to 75 ohm conversion.
Mike, go through the forum wiki - there is a note about using 75 ohm modified firmware that will work on any of the original? and H nanos (not the H4).
The firmware is in the files section.
toggle quoted message
Show quoted text
On Friday, July 9, 2021, 9:44:44 a.m. EDT, Mikek <amdx@...> wrote:
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?
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Re: Antenna Tuner with NanoVNA incorporated.
Saw this the other day on Instructables ¡ª 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@...
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Re: Antenna Queries de k3eui Barry prior to Nano VNA talk
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 !
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That pesky 50 to 75 ohm conversion.
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?
|
Re: Antenna Queries de k3eui Barry prior to Nano VNA talk
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).
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Re: Antenna Queries de k3eui Barry prior to Nano VNA talk
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
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Re: Antenna Tuner with NanoVNA incorporated.
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.
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Re: More "what clone version I have " question
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.
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Re: Running nanoVNA - saver using Ubuntu (desktop )
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¡¯.
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Re: More "what clone version I have " question
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.
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Larry Dodd
Barry K3EUI
W4MTM Dale Beach
Ho-Ro