On Tue, Oct 13, 2020 at 01:47 PM, Roger Need wrote:

From the above you can see that once you get above 500 ohms small measurement errors of the reflection coefficient will result in large errors in the estimate of Z.?? So it is not possible to accurately measure Z in the thousands of ohms (which is what you want to do if measuring RF chokes)? with a one port VNA like the RigExpert.? It is possible using a 2 port VNA using what is known as the S21 method but this requires a high end VNA in order to get accurate results.?

hello everyone,
nice to see a group dedicated to rigexpert product. I personally own a AA-54 and I'm looking to add a stick 230 to my arsenal in the near future.

Forgive me if I reply to an old post but I was studying why in the stick 230 there is a page with "mag." reading with values different from the impedance magnitude.
I used one of my script calculator and found out "mag." is the reflected coefficient and from this post I understood it's more precisely the reflected magnitude
(seems like when I wrote my calculator I was lazy enough to miss reflected coefficient angle).

I have a question regarding the examples mentioned: if I set the Zo to 600 to measure a high impedance choke do I get a better reading (in the sense of more accurate)
or changing the source impedance is merely a matter of math inside the firmware with no real benefit on the actual reading (ADC still working on 50 ohm)?

for example with Zo 600 ohm and ZL 3000:? Γ mag. = 0.667

many thanks in advance
Luigi IU2GID

I made some progress; now I got rid of the garbage, at least...

Here is my VERY RUDE, UNOPTIMIZED, UGLY and EXPERIMENTAL CODE that perform a 200khz sweep
I used various pieces of code I found and added something by myself.

I am not a developer (it's evident...).

The conclusion is that it takes 12 seconds to scan a 200khz range with 4khz steps using the "forr loop" method
and it takes 8 seconds to do the same using sw and frx span parameters....

I guess my code could perform way better than this...
Tthe goal now is to understand if it would be faster anyway to use ZERO automatic multi measurement or to spend time to optimize the code....

Any suggestion ?

Thanks

-----?

#include <SoftwareSerial.h>

// enable this for additional debugging output
#define DEBUG_OUTPUT

SoftwareSerial ZERO(4, 7);? // RX, TX
char fq[30]="";
int go = 0;


// response string buffer
String _resp;

// for holding the parsed response data
struct
{
? float freq;
? float resist;?? // resistive measurement
? float react;??? // reactive measurement
? float swr;????? // computed SWR
? float gamma;??? // computed Gamma
} _respData;



? double current_freq_KHz=0;
? double Fstart_KHz=7000;
? double Fstop_KHz=7200;
? double Fstep_KHz = 4;
? int num_steps=(Fstop_KHz - Fstart_KHz) / Fstep_KHz;
? double swrmin,swrtmp,temp;
? double swrminFq;
? double Gmin=10;

void setup()
{
? // initiaize ZERO UART
? ZERO.begin(38400);??????? // init AA side UART
? ZERO.flush();
? ZERO.listen();??????????? // implicit, but just for good measure

? // initialize debug output
? Serial.begin(38400);?? // make sure the serial monitor doesn't slow us down
? Serial.flush();
?
?
}


void loop()
{
? if (go == 0)
? {
?? ?
??? sweep_multi(); //This sweeps using for loop : 12 seconds to perform 200khz with 4khz sampling
??? //sweep(); // This sweeps using ZERO swXXX and frxXXX : 8 seconds to perform 200khz with 4khz sampling
?? ?
??? go=1; //uncomment to execute once
??? //delay(1000);
? }
?
?
?
}

void sendCommand(char cmd[])
{
?
? //ZERO.println(cmd);
? //delay(100);
? int l=strlen(cmd);

?? ?
? for (int i = 0; i<strlen(cmd); i++)
? {
?? ?
??? ZERO.write(cmd[i]);
? ?
? }

?
??? _resp = ZERO.readStringUntil('\n');
??? if (_resp!="OK\r")
??? {
????? //Serial.println(_resp);
????? parseData();
????? //displayResults();
??? }
?

}


void sendCommand_multi(char cmd[])
{
?
? //ZERO.println(cmd);
? //delay(100);
? int l=strlen(cmd);

?? ?
? for (int i = 0; i<strlen(cmd); i++)
? {
??? ZERO.write(cmd[i]);
? }

? for (int ii=0; ii<50; ii++)
? {
? _resp = ZERO.readStringUntil('\n');
? parseData();
? }
?? ?
}


void parseData()
{
? char parseLine[40];
? char parseTemp[40];
? int k=0;
?
? _resp.toCharArray(parseLine, sizeof(parseLine));
?
? //Strips the dot from freqency in order to make its atof conversion working (because response from ZERO uses the "." as thousand divider as well as decimal divider...)
? //Assuming the frequency dot character is one of the first 4 received from ZERO.
? //Remaining dots has to be preserved because they are real decimals
? //
? for (int i=0; i<sizeof(parseLine); i++)
? {
??? if ((parseLine[i]!='.') || (i>3))
??? {
????? (parseTemp[k] = parseLine[i]);
????? k=k+1;
??? }
? }
?
? //char *p = parseLine;
? char *p = parseTemp;

? _respData.freq = atof(strtok_r(p, ",", &p));
?
? //p=NULL;
? _respData.resist = atof(strtok_r(p, ",", &p));
? _respData.react = atof(strtok_r(p, ",", &p));
? //_respData.swr = computeSWR();

? //
? // Compute SWR from R & X
? //
? float XX = _respData.react * _respData.react;
? float Rm = (_respData.resist - 50) * (_respData.resist - 50);
? float Rp = (_respData.resist + 50) * (_respData.resist + 50);
? float N = sqrt(Rm + XX);
? float D = sqrt(Rp + XX);
? float G = N / D;
? float vswr = (1 + G) / (1 - G);
?
? _respData.gamma = G;
? _respData.swr = vswr;



? if (G<Gmin)
? {
??? Gmin=_respData.gamma;
??? swrminFq=_respData.freq;
??? swrmin=_respData.swr;
? }
?
}

void displayResults()
{
? Serial.print(" Freq: ");
? Serial.print(swrminFq);
? Serial.print(" Gamma: ");
? Serial.print(Gmin);
? Serial.print(" SWR: ");
? Serial.println(swrmin);

}


void sweep()
{
? char fq2[30];
?
? //Serial.println(num_steps);
? for (int z = 0; z <= (num_steps); z++)
? {
??? // Calculate current frequency
??? current_freq_KHz = Fstart_KHz + (z) * Fstep_KHz;
??? strcpy(fq,"fq");
??? dtostrf(current_freq_KHz*1000,9,0,fq2);
??? strcat(fq,fq2);
??? //Serial.println(fq[0]);

??? strcat(fq,'\n');
??? //Serial.println(fq[0]);
??? sendCommand(fq);
?? ?
??? strncpy(fq,"sw0\n",30);
??? sendCommand(fq);
??? delay(5);
?? ?
??? strncpy(fq,"frx0\n",30);
??? sendCommand(fq);

????? ?
? }
? displayResults();
}

void sweep_multi()
{
? char fq2[30];
?
? //Serial.println(num_steps);
?
?
??? // Calculate current frequency
??? current_freq_KHz = Fstart_KHz + ((Fstop_KHz - Fstart_KHz)/2);
??? strcpy(fq,"fq");
??? dtostrf(current_freq_KHz*1000,9,0,fq2);
??? strcat(fq,fq2);
??? //Serial.println(fq[0]);

??? strcat(fq,'\n');
??? //Serial.println(fq[0]);
??? sendCommand(fq);
?? ?
??? strncpy(fq,"sw200000\n",30);
??? sendCommand(fq);
??? delay(5);
?? ?
??? strncpy(fq,"frx50\n",30);
??? sendCommand_multi(fq);

????? ?
?
? displayResults();
}




-------------------------------

Hello,
I spent some days trying and failing to deal with serial communications between Arduino (uno) and the ZERO.
The main problem here is the randomness I get when I write something to ZERO.serial and try to get back the results....
1) lot of time I get garbage (and yes, my serial settings are ok, even in the arduino IDE monitor)
2) I took a look to a lot of examples found on the net, but I am not able to understand if it would be better to send/receive commands using strings or array of bytes
3) the timing waiting for ZERO responses seems to be unpredictable; take the rigexpert example here:

at the bottom of the page example (last one)
code snippet (when writing a command to the ZERO, and then waiting for the response):

---------------------------------
ZERO.write(ch);
? ? ? ? if (ch == '\n')
? ? ? ? {
? ? ? ? ? for (int d = 0; d < 50; d++)
? ? ? ? ? {
? ? ? ? ? ? delay(1);
? ? ? ? ? ? if (ZERO.available())
? ? ? ? ? ? {
? ? ? ? ? ? ? Serial.write(ZERO.read()); // data stream from AA to PC
? ? ? ? ? ? }
? ? ? ? ? }
-------------------------

What is the purpose of that? FOR loop "int d"? ???
I guess it is a timinig thing.... that does not work for me... infact I have to change d<50 to d<150 to increase it in order to make it working.

But again it seems to be all confusing...
If I cut and paste that example it works (modifying the "d" ) , but when I try to implement a simple sketch to just take a command with fqxxxx sw0 frx0 and reading back the single reading , (so without input the command by hand via serial console, but let the sketck do it without human intervention) I am not able to get useful results...

To summarize, my first goal is to have a simple sketch that:
take a frequency to put in a a"command" (with sw0 and frx0)? that is a variable into the sketch, not a human manual input
sent to the ZERO
get the result back
print to the console the result

(then I will put this in a way to sweep between frequences, and interpret the results, but this is step 2)


Advise welcome.
Thanks



This is my minimal code that is giving garbage output, for example... (it gives "AA-30 Demo" and then on a new line , two mirrored question marks garbage)
No matter if I use 9600 or 38400 bps
No matter if I use the while (at the end) or if I use a "readstringuntil"



#include <SoftwareSerial.h>

// enable this for additional debugging output
#define DEBUG_OUTPUT

SoftwareSerial ZERO(4, 7);? // RX, TX
char fq[]="fq14200000";
int go = 0;

void setup()
{
? // initiaize ZERO UART
? ZERO.begin(38400);??????? // init AA side UART
? ZERO.flush();
? ZERO.listen();??????????? // implicit, but just for good measure

? // initialize debug output
? Serial.begin(9600);?? // make sure the serial monitor doesn't slow us down
? Serial.flush();
? Serial.println("AA-30 Demo"); // show that the output port is working
?
}


void loop()
{
? if (go == 0)
? {
??? sendCommand(fq);
??? go=1;
? }
?
?
?
}

void sendCommand(char cmd[])
{
? String _resp;
? ZERO.println(cmd);
? delay(100);

? _resp = ZERO.readStringUntil('\n');
? Serial.println(_resp);
?
? /*while (ZERO.available()>0)
? {
??? Serial.write(ZERO.read());
??? delay(10);
? }*/
?
}

Hi Alex,

? ? I am unable to view the video. When I go to the link you provided I get a message saying I am unable to watch the video because it is private.

My problem starts when I attempt to view a saved memory from the AA-35. ?
? ??
? ? ?I open Antscope2... connect the analyzer to my laptop via the supplied USB cable...I then click on "Data from AA".....a window opens up allowing me to choose what data to look at on Antscope...I select the data I want to see...click "ok" (or double click) ...and the only data I can view shows up under the Smith chart tab, there is nothing under all other tabs (SWR,...etc)

? ?Thanks, Evan

Hi Alex....Thanks for the response, but Antscope2 still does not appear to be functioning correctly. I loaded firmware version 1.12 into the analyzer and when I try to view a saved measurement the only tab that shows the data is the Smith chart. ?The other tabs show nothing. I am using the latest version of Antscope2. Do you have any other suggestions?

Thanks, Evan

Alex,

It has been over a month now since the beta version of the AA-55 Zoom software was released for testing and nothing has been heard from RigExpert since then.? Many of us are waiting for a good Bluetooth fix for our AA-55 Zoom that cost us a lot of money.

Frank and Doug took the time to send you detailed beta test reports and you have just ignored them which is not very polite. You reply to other inquiries in this group but not to them? I just don't understand why RigExpert treats their customers this way.??

Roger

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Hi!

We are working on analyzer models above 2 GHz.
But I still cannot name an approximate date of launching new analyzers into production.

Regards, Alex UR4MCB

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Dear Evan,

Most likely your analyzer has firmware version 1.14?
If so, this is a known issue. It will be fixed in a new version of the FW.

For now, you can manually install firmware 1.12 into the analyzer.
Link:
This firmware version does not contain a bug with loading saved measurement results.

Regards, Alex

Hi all.....Having trouble opening saved data from the AA-35. ?I open Antscope2, click on "Data from AA" , I select the saved memory that I want to see, I see the selected memory go into the window on the lower right, but when I click "open" a window opens prompting me to choose a file from a location on my computer...I'm using a Mac ( don't know if that matters). I thought by selecting the memory from the "Data from AA" button would load the file I want. Regardless, I can't seem to get a saved memory from the AA-35 to my computer. ?If someone could help me out with this issue it would be greatly appreciated. ??

Thanks..Evan

Hi

Are there any plan to make antenna analyzer for 2.45 GHz ?

We are popular satellite? ? QO-100? on 2.4XX GHz? and not easy to messure cable loss or SWR in that freq
So big question if RigExpert would make one type for us ?

73
TF1A

aa-650-zoom... what's the difference between the 600 & 650

I am currently using a aa-55-zoom that's less than a year old and now but I'm ready to bump it up.? also, you received a 2 year warranty if you purchased directly from rigexpert but now, all I see is authorized dealers / resellers?? has the warranty changed, must I now buy from an r&l, hro or gigaparts?? and what about the 2 years warranty, is that still the norm?

Hi,

I already posted this AntScope 1.1.4 bug more than one month ago in GitHub () but didn't see a reaction, so I try it here as well.

I also checked the issue with test version 1.1.5, but it leads to the same behavior, which shows different values when one compares the measured VSWR graph against the printed graph. Pretty bad when one wants to create a document with measured data.

Further, compared to earlier versions, the ham bands in the printout are not highlighted.

And last but not least, when using the [Print] function and saving the smith chart as .png, the resulting smith chart image is skewed.

All issues can be reproduced with two PCs under MS Windows 10.

Thanks for looking at.

Best,
Stephan

Thanks a lot Doug
Lot of tips here.... I am going to take this infos and do some test.

best 73!

On Tue, Mar 9, 2021 at 05:50 AM, Brian Miller wrote:

Sorry - I meant to say that the stub tuner tool displays 3460 kHz and the RX chart displays the resonance at 3540 kHz, I.e. a difference of 90 kHz. So which one is more correct?

When you measure a stub you need to use a short circuit at the end for half-wavelength and open circuit for quarter wavelength.? This gives the steepest transition for X and the correct result.? This is described on page 18 of the user manual but unfortunately not in the Stub tool section or on the analyzer itself.??



I did some measurements of on a 31 foot piece of RG-58.? Here are the results using the RX method and the Stub tool method

RX measurement:
-? Quarter wavelength frequency = 4.987 MHz. with open circuit at end? ** correct method
-? Quarter wavelength frequency = 4.981 MHz. with short circuit at end?

-? Half wavelength frequency = 10.009 MHz. with open circuit at end
-? Half wavelength frequency = 10.034 MHz. with short circuit at end? ? ???** correct method

Stub tool measurement:
-? Quarter wavelength frequency = 4.987 MHz. with open circuit at end? ** correct method
-? Quarter wavelength frequency = 4.981 MHz. with short circuit at end?

-? Half wavelength frequency = 10.133 MHz. with open circuit at end
-? Half wavelength frequency = 10.038 MHz. with short circuit at end? ? ???** correct method

You will note both techniques give the same answer to with in a few hertz. when terminated correctly.??

ATTN. RigExpert support -??I was using beta firmware 1.26 to do these tests.? It occasionally stopped scanning and froze when using the Stub Tool with no results screen displayed.? After displaying the final values it always crashed with a flashing screen and I had to power off the AA-55 Zoom and power back on to get to the main menu.? I don't know if it does this with previous versions of the firmware.? Perhaps other users can comment on this bug.

Doug VE7DXK

On Tue, Mar 9, 2021 at 05:21 AM, <swanawood@...> wrote:

Thanks Doug,
when you say : "...write your own code to send commands to the Zero? and process the returned ASCII data" , do you mean to interact with ZERO via serial TTL port using those commands ?

Yes.? You don't need to use the Arduino library to communicate with the Zero.? You can just send it commands to set the frequency, number of measurements etc.? as shown below over the serial TTL interface.?


You send these commands over the serial TTL interface and it returns R and X.? A couple of things to consider....

• The Zero can take some time to transfer the data.? A 100 points for example can take several seconds. The fewer points the better for your application.? You can measure at one frequency (the one you want to tune to) by using the "sw0" command .? It is sw0 and not sw1 because it always return N+1 data points so with N=0 you get 1.? This should be quite quick and you can step the capacitor, read one value from the Zero and then decide whether to go clockwise or counter-clockwise with the tuning capacitor

• The values returned are in the form R (resistance) and X (reactance).? You need to do some math to convert these into something that indicates when the antenna is giving you the best match.? You might be tempted to tune for X=0 but this does not necessarily give you the best match.? You can do the math to convert R&X to SWR but it is faster to calculate rho (p) which is the absolute magnitude of the reflection coefficient.? Rho is? better because it is a number from 0 to 1 with 0 being the best match possible.? SWR can be calculated if desired using the formula SWR = (1+p)/(1-p).? Take a look at the RigExpert sample code to see how to convert R and X to the reflection coefficient.?

Best of luck with your project

Doug

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Yes, please.?

Hi Alex,

I hope you are feeling well today.

It's been a couple of weeks since Doug and I posted our tests and results. I'm not sure if you have any more beta testers on this issue or not. However, could you post a reply as to what RigExpert's next steps are and some time-table for finalizing the Bluetooth connectivity fix for the AA-55 Zoom?

Sincerely,

Frank
K4FMH

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Sorry - I meant to say that the stub tuner tool displays 3460 kHz and the RX chart displays the resonance at 3540 kHz, I.e. a difference of 90 kHz. So which one is more correct?

I'm using the AA-55 ZOOM to trim RG11 coax to an electrical length of a halfwave at 3500 kHz. The stub tuner tool shows the current length as being a halfwave at around 3560 kHz with the far end open circuit but the RC chart tool shows the resonance (where the reactance sign changes polarity) as being around 3540 kHz with either an open or short circuit at the far end. Any thoughts on why am I seeing this much variation between the different tools within the analyser? Which tool can I rely on to give the most accurate result in this situation?