Tremolat

Happy new year 2025 ! Two KiwiSDR, AutreRadioAutreCulture, Trémolat, Nouvelle Aquitaine, France. Ask for a password to access it. Demandez un mot de passe pour y accéder.

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Tremolat
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  • Confirming what I need for a Kiwi 2 board

    TremolatTremolat

    Hello,

    I'm listening to your receiver from Nouvelle-Aquitaine, France, Trémolat. The computer part, the stream, is very stable; that's already excellent. Now we need to improve the RF section and especially increase the gain on the shortwave band. First, eliminate all the electrical interference that travels from band to band: power supply issues, grounding problems, ground loops. You need to work on all these avenues very meticulously.

    A filter around 580 kHz is essential. The strength of the received CFRA station and its proximity prevent good reception. It completely overwhelms the signal. Building such a notch filter is not very complicated. The filter offered for sale gives very good results.

    Best regards, Philippe

    va3xa

  • Interference & a Galvanic isolator

    TremolatTremolat

    Dear all,

    this is why I have moved the receiving antennas as far away from buildings as possible. The antenna of my KiwiSDR #1 is 50 meters away. The antenna of KiwiSDR #2 is 250 meters away. The 75 ohm lines are buried about 40 cm. This is the only valid solution I have found to eliminate all this radio interference from domestic appliances using a switching power supply.

    I also have 32 photovoltaic panels (12 kWp three-phase), which doesn't interfere with KiwiSDR reception, provided the installation is well filtered.

    The neutral system on the electrical installation is IT (230 V). This means that there is no neutral and the mains power supply is symmetrical (two-phase).

    I hope this helps. Happy RFI hunting. Best regards, Philippe

    F5AFY

  • Quiet switch mode power supply (SMPS) for KiwiSDR

    TremolatTremolat

    Hello FrankinAu, you have in the following document, pages #7, #8 and #9, my example of the casing of my two KiwiSDRs. This can give you some ideas.

    http://labroue.autreradioautreculture.com/Courdilles/KiwiSDR/Documents/Description_KiwiSDR_Tremolat.pdf

    The fan (brushless) is also powered by 12-15 Volts, in parallel with the current injector in the antenna. I preferred to add copper shielding. And place the boxes in a 19-inch rack bay. The parasite spectrum obtained is on page #11 (LNA and protections are connected for this test).

    Best regards, Philippe

    studentkraSV1XVblurryface