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Release Firmware CEC Version 0.1 for Antenna Analyzer(EU1KY)

Release Firmware CEC Version 0.1 for Antenna Analyzer(EU1KY)

I would like to thank EU1KY and DH1AFK OM for making and improving this wonderful antenna analyzer. The Antenna Analyzer is already perfect enough. I just want to add a little bit. This project will continue until CEC Version 1.0.

1.Introduction -
5.Principle of Antenna Analyzer
6.Antenna Analyzer Firmware Improvement (this article)

1.Improvements in CEC Version 0.1
 1.1 Program stabilized 
     Did Antenna Analyzer occasionally freeze during operation? People around me and me have often had that experience. If you have such experience, please upload and test this firmware. I would really appreciate it if you could let us know your test results in this post comment or in my email.
I have fixed a few things for stability.

 1.2 Improve measurement speed
     I increased the speed by adding a little extra code when measuring the frequency range.

 1.3 GUI
    Frequently used is an icon on the desktop. but this is not fixed. It may change several times until it becomes CEC Version 1.0.

 1.4 Tracking Scope
    I have several VNA and I use it mainly to measure filters when I use VNA for amateur radio.

    The high-end Spectrum Analyzer has RF Generator Mode, sets the tracking mode, and measures the transmission characteristics according to frequency.  It is similar to S2 -> S1 measurement of VNA. (Phase measurement excluded)

   That's what I created.

   To do this, the S2 port must be added. The S2 port is simply connected to the CLK2 of the Si5351. CLK2 is an unused PIN.
Please see below link for details.

 If you need more advanced VNA functionality in addition to Tracking Scope mode, we can make it together. But the RF board seems to have to be redesigned.

There was an opinion of DH1AKF. It is not necessary to test the filter and the transmission line which are not connected to electricity like me, but if you need to measure directly by using the probe on the PCB with the electronic parts, you can use 2 ~ 3 resistors and 1 capacitor You will be able to add. (The performance of the tracking scope may be degraded if you apply this)

I am making another Antenna Analyzer, and I will apply Probe Safety there.

2.Download Link

Please refer to the link below for how to update the firmware.

The source code will be released through the github or zip file at the end of the Beta version.

3.How to use
The EU1KY Antenna Analyzer is already in wide use and you can easily find the usage on the Internet.

The video below shows an example of using the Tracking Scope, an added feature.

How to use Tracking scope has been registered as a subtitle in the video above.
The pictures below are capturing only the main parts.

Probe for measurement

Connect to S1, S2

Calibration for Tracking Scope function

Test filter ( Low pass filter for ~ 5Mhz)

Measurement result 1

Measurement result 2

I will post more examples of using the Tracking scope feature.
This project will continue until CEC Version 1.0. If you want to be added, please email me.

Thanks for reading.


  1. Nice work, Ian. I have one of Yuri's AAs for a year or so now. I only discovered Wolfgang;s modified firmware recently, and now your also. We are spoiled for choice. Dan Marks has developed a board based on Yuri's board, but it is 2-port.


    1. Thanks for the good info, I want to make another on this great platform. If someone is running a VNA project, I have to add another funny thing.

      If I had known that there was such a wonderful AA, I would have participated in the project a little early. I was a while ago.

      Best 73

      Ian KD8CEC

    2. Jan, thanks for the beautiful menu in AA. Already made a scanner. At the output of the CLK 2, the capacitor 100n was soldered in series. Working OK . But I wanted this feature to also have the ability to continuously scan. Very useful when setting the filters ....
      Thanks and my respect LY2BOK Justas

    3. LY2BOK
      Excellent, It seems to be safer because of capacitor. Thank you for your information. Since the output of CLK2 is only about 8mA, I must follow your method.
      I agree with your opinion. Continuous measurement function will be included in Version 0.2.

      Ian KD8CEC

  2. I have built the Analyser from the beginning of conception and upgraded to the various upgraded firmwares by DH1AKF.
    Thank you for your contribution and I am looking forward to further upgrades.
    (there is a typo in the calibration menu TX(S2) "Calibration" is misspelled) :)
    John VK5COR

    1. John

      I am so sad that I knew this AA now. I bought a portable VNA and another antenna analyzer about a year ago.
      Calibration will be corrected immediately.

      Ian KD8CEC

  3. Wonderful, the function is very useful.

    Thank you very much
    73 Victor YO3DEX

  4. Hello Ian,

    Have you seen this useful analyzer too? (use Google translate)

    I have ordered parts and wait for delivery from China...


    Nigel - G4ZAL

    1. Nigel
      Today I saw a wonderful project because of you.
      I will studying the translated posting
      Thank for good information.

      Ian KD8CEC

    2. Ian,
      Great, I would be very interested if you decide to build OM JA2NKD's analyzer (and maybe make some improvements ;-) ).
      If you do, be aware NOT to ground the input coax connector!
      Video -
      Code -


  5. Ian KD8CEC, you will be interesting information from LY3BD Alexander about new function of the device.

    Post # 1346.
    LY2BOK Justas

    1. Justas
      it is awesome. Thanks for introducing a good community. There have already been various experiments in the community.
      I have been very helpful in determining capacitor value for DC blocks.
      If you come up with good content for the community, let me introduce you again, I'll try to connect you sometimes.

      Ian KD8CEC

  6. Small adjustments:
    1. In the new menu when you click the pictures there is no sound signal.
    2.In the menu window, after switching from another function, there is no indication for a very long time of the battery voltage. About 25-30 sec.
    Justas LY2BOK

    1. Justas
      Thank you for your kind comments. I will add it to Todo list.


  7. This comment has been removed by the author.


  8. Hi Ian,
    next days I will test your hard- and software modifications. Thank you very much for these improvements!

    You have named the additional menu "S2>S1 (Tracking Scope)". I would suggest another headline, (like in the literature):

    |S21| (Gain)

    S21 is a stray parameter in the theory of 2- port networks, but you only get the real part of this parameter.

    I'm looking forward to the source files.
    73, Wolfgang (DH1AKF)

    1. Wolfgang
      Thank you for your suggestion. It is a proper name.
      I was worried. It is called Transmission Mode and also called 21 Chart when measuring in VNA. I will apply in the next version (name is S21 Gain or S21(Gain))

      I've been doing quite a variety of things, and the code is a lot dirty.
      Please wait for the source code. If the experimental code is deleted before the beta version is finished, I will send it to you first.

      Ian KD8CEC

    2. Wolfgang
      Could you give me your e-mail address?
      There are still a lot of test codes for debugging in the code, but I have put it a bit for you. I am going to post it on github after the code is cleaned up, but if you do not mind debugging code, I will send you the source code.

      Ian KD8CEC

  9. Hello Ian.
    I think that in the device with your modifications, in the <> mode you need to use the CLK2 output of the si5351 chip.
    This does not apply to the < S2>> mode.
    Sergey RX9A 73.

    1. Sergey

      Yes, that's right.
      transmits measurement propagation to CLK2 in Tracking scope (new name is S21 (Gain)) , And CLK1 generates the necessary signal in the mixer to down the received signal to 48Khz. So the signal from CLK2 could go through the DSP routine via VI.
      Since OSL can not be applied at that time, phase can not be obtained and only gain can be obtained. I was worried about naming this feature because it is not the result of the perfect VNA S21.

      Please leave a comment if you have a good opinion at any time.

      Ian Kd8CEC

    2. This comment has been removed by the author.

    3. Good afternoon ,Ian
      We are waiting for the version that we already looked at on YouTube. There is such a desire that you integrate the work on the improvement of the program, with DH1AKF Wolfgang. And now it turns out like two devices. Wolfgang has a new offer and You have new items. We want everything in one ......Please, if it can.

      Justas LY2BOK , Aleksandr LY3BD .

    4. The firmware that was shown on YouTube has already been released on this blog.

      I am still in the experimental stage. And integration is always good. I think it will become a more wonderful analyzer.

      Thanks for your suggestion

      Ian KD8CEC

  10. Hello Ian,
    after fiddeling with three memories for storing the 401 complex measured data, I made a new version of my software. Now the window "Frequency Sweep" is enhanced.
    Here is the source:

    It would be very interesting, to build a conglomerate of our different versions.
    But I imagine, that this is a lot of work...
    73's Wolfgang (DH1AKF)

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