Hem SAQ Forum SAQ Technical Discussions Optimize the signal i received.

  • Skapare
    Ämne
  • #12700 Svara
    Eelco de GraaffEelco
    Deltagare

    Hi, i was able to decode the message transmitted by SAQ 24-12-2024 (saq twente) and i also used my own receiver (saq opname).
    In the noise there is a signal but it is not good enough to decode with the gerke-decoder.
    Is it possible to improve the recorded signal in a way the gerke-decoder could decode the transmission?
    I have made the recording with audacity and the recording is named saq opname.aup3 and can be downloaded here.
    https://edegraaff.stackstorage.com/s/bMNytHyRwB9rFEGC
    I am curious if the recording could be improved and how.

    Regards
    Eelco de PD1EG
    More about the SAQ project at my blog https://www.fishfreak.org/sdr/

    • Detta ämne redigerades för 5 månader sedan av Eelco de GraaffEelco.
    • Detta ämne redigerades för 5 månader sedan av Eelco de GraaffEelco. Anledning: Improve text
Visar 2 svarstrådar
  • Författare
    Svar
    • #12937 Svara
      Richard Williamsrich.g.williams
      Deltagare

      I ran through your “saq opname” files and there is no sign of the SAQ CW at 17,200Hz running it through Audacity just confirmed there is nothing.

      You might have more success with a big vertical loop with the plane of the loop pointing towards SAQ. Both end wires need to be terminated at the receiver and one end also Earthed.

      Hope that helps.

      • #12938 Svara
        Eelco de GraaffEelco
        Deltagare

        Hi Rich, thanks for the tips. I will give it another try next time. I will add the earth as extra and see if it improves the signal. Ther is a lot QRN here so maybe i would even search for a better location during the transmittion.
        Regards Eelco.

    • #12717 Svara
      Richard Williamsrich.g.williams
      Deltagare

      PS I just had a look at your project file “saq opname.aup3” and unfortunately I can’t see any valid VLF there setting the waveform to spectral view. Looks like something has gone wrong and you are not recording VLF, should be frequencies up to about 21KHz. The spectral view should show several VLF stations with SAQ at 17.2KHZ but I don’t see any VLF stations in your file on the spectral view.

      Rich

    • #12715 Svara
      Richard Williamsrich.g.williams
      Deltagare

      Hi Eelco.

      Suggest you can have a look at Listen to SAQ Its on this site its on “SAQ in the ether” then “Listen to SAQ” and scroll down to the title “Reception using an audio editor”

      It shows how you can setup Audacity’s filter curve to pass a very narrow band of frequencies around 17.2 KHz then it shows how to shift the pitch right down to 750 Hz. Then you can hear the morse code.

      Then save the audio file and try it with the gerke-decoder.

      Hope that helps,

      Rich

      • #12725 Svara
        Eelco de GraaffEelco
        Gäst

        Hi, you’re right, I have done this with my previous recording, I will give it a try.

        • Det här svaret redigerades för 4 månader, 3 veckor sedan av Fredrik WiklundAlexanderSAQ.
        • Det här svaret redigerades för 4 månader, 3 veckor sedan av Fredrik WiklundAlexanderSAQ.
Visar 2 svarstrådar
Svar till: Optimize the signal i received.
Information om dig:





Subscribe!

Be the first to know about upcoming SAQ transmissions by subscribing to our newsletter.

No, thanks!