EU1KY Antenna analyzer with STM32F7Disco (DH1AKF mods)

Discussion in 'Homebrew and Kit Projects' started by DH1AKF, Jan 10, 2018.

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  1. DH1AKF

    DH1AKF Ham Member QRZ Page

    Here is the answer from Yury, EU1KY:
    >>DH1AKF, it's not that simple. The HW Calibration linearly compensates for phase and amplitude differences in mixers and the low-frequency path. That is, it calculates the factor by which you need to multiply the amplitude of one of the channels and the correction for the phase, with identical bridge arms (with a 51 Ohm resistor instead of the load). Without this compensation, OSL calibration may simply fail when the current and voltage phase difference is >90 degrees. The measured impedance calculated by Ohm's law may have negative R, which in principle should not be the case, or the module of the reflection coefficient calculated from the impedance will be greater than 1. What to do with such values? Do not apply OSL calibration to them in any way, as the results will be absolutely wrong. They will not be displayed on the Smith diagram, as they will fall outside of it.
    And if a 50 Ohm resistor is connected to the bridge through a connector and an unknown piece of cable, it is unlikely that the bridge will see it as exactly 51 Ohm and the corrections will be incorrect. With all the above consequences.<<
     
  2. IU5IWS

    IU5IWS Ham Member QRZ Page

    Good evening! I recently purchased the Mini1300 and I'm trying to understand how it works. I have read some discussions of Eu1ky where it illustrates the possibility of connecting to the PC using AntScope software for RigExpert, from tests made my analyzer is not detected by the PC and by the program. Do you have any suggestions to give me?
    Thanks for an answer.
     
  3. DH1AKF

    DH1AKF Ham Member QRZ Page

    Look, here's the manual:
    http://wkiefer.de/x28/test/Analysator_1.6_English.pdf

    >>10 Software «AntScope» In the main menu, the device can be remotely controlled via the USB connection ST-Link with the software AntScope. The measurement results are also available in numerical form and can be used for further calculations or simulatins. Before operating with AntScope , the driver for the STM32 Disco card must be installed. First select the COM port in the AntScope program and select the option AA-600 Analyzer (RigExpert ) as the measuring device.<<
    The USB driver is here to find:
    https://www.st.com/en/development-tools/stsw-link009.html

    Remarks: The new program "AntScope2" cannot be connected to the EU1KY analyzer, (because of a new protocol).

    == There is a newsgroup, dedicated to the EU1KY analyzer:
    https://groups.io/g/Analyzer-EU1KY
     
  4. IU5IWS

    IU5IWS Ham Member QRZ Page

    Thanks Wolfgang! I downloaded the STM drivers and it works with AntScope. Thanks for the work done to the whole group, an excellent antenna analyzer with many functions at a reasonable cost.
    73 de Giampiero
     
  5. DH1AKF

    DH1AKF Ham Member QRZ Page

    New Firmware (for DH1AKF variant)
    The reason for the program change was a faulty calculation in the module "LC- Match", which is located in the "Measurement" window.
    The firmware 2020_02_23 20:40 UT is in the network:
    http://wkiefer.de/x28/test/F7Discovery.bin
     
  6. DH1AKF

    DH1AKF Ham Member QRZ Page

  7. DH1AKF

    DH1AKF Ham Member QRZ Page

    FT4, FT8, JT65 transmitting tested

    The SI5351 delivers approx. 10 mW into 50 Ohm.
    With a radio friend, who lives about 500 m away (DH1AKG), it was possible
    successfully in FT4 and FT8 operating modes to decode my signal. We used
    the 30m band.
    Today a transmission to DK4RC (approx. 17 km distance) on 144
    MHz succeeded. However, he had connected his EME antenna and exactly
    aligned. I used a 3 element Yagi. The transmission
    was done in JT65A, my signal was perfect with -19 dB SNR
    decoded.
    Many thanks to Ian Lee, KD8CEC for his excellent work!
     
  8. AB6RF

    AB6RF Ham Member QRZ Page

    I recently changed my EU1KY analyzer to the DH1AFK SW, and now I seem to have this persistent problem.
    The frequency sweep plots have this "sawtooth" pattern that repeats exactly every 100kHz.
    Almost like the HW cal, or the OSL cal, has very poor resolution.

    I keep reformatting the SD card, and re-running the HW calibration as I'm testing new RF chokes on the RF board.
    But it doesn't help, the issue keeps being there.

    I've set the OSL and frequency sweep averaging to 5, but it doesn't help.
    In the Configurations my Si5351 Max Freq is set to 260MHz, Min Frq = 500kHz and Max Frq = 500MHz.

    What might cause results like this?

    (2M band, S11 and R & X into 50ohm load)
    [​IMG]
    [​IMG]

    (40M band, S11 and R & X into 50ohm load)
    [​IMG]
    [​IMG]

    Mikko, AB6RF
     
  9. AB6RF

    AB6RF Ham Member QRZ Page

    For a reference, here's my Generator and DSP screens, with the RF jumper in HWCal position.
    To me it looks like the RF board, and signal sampling is working fine.

    [​IMG]

    [​IMG]
     

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