Posts by DK8KW

    Hello all,


    The SDRuno-Software in combination with one of the SDRPplay-devices (I use the RSP1A) is capable to measure/estimate the SNR reasonably well. The SNR is calculated based upon the selected bandwidth.


    To quote SDRplay Tech_Support:.


    "The SNR measurement is only for the selected signal as defined by the filter bandwidth defined within the Rx Control panel. The signal power is taken from the power meter measurement and the noise is estimated via an analysis of the entire wider band noise floor within the SP1 window to remove the effect of the presence of other signals. As such, the SNR measurement is not a precise measurement, but it is reasonably accurate."


    [see: https://www.sdrplay.com/community/viewtopic.php?t=2947]



    Vy 73


    Holger 'Geri', DK8KW

    Hi all,


    Thanks to all the hints from Marcel and others here in the forum I have managed to successfully watch a number of DATV transmissions in the meantime.


    Two things were particularly helpful: more computer power (I upgraded my PC from a dual core to a quad core) and the increase in signal strength. Sinde a few days I do have a 1.8m offset dish from Kathrein standing in my garden and the improved signal to noise ratio definetely has reduced the required computing load during decoding of the signals.


    I am looking forward to the next version. Thanks, Marcel, for working on this software!



    Vy 73


    Holger ‚Geri‘, DK8KW

    Hi,


    After finding a (relatively) cheap Quadcore-Computer (Intel Q8400) reception now works fine, using an RSP1A and a modified Octagon (IF around 435 MHz) in a 85 cm offset-dish.


    Finding rhe right parameters still meams fiddling around a little bit but once I hit the proper parameters the stream starts and the video is escellent.


    Thanks, Marcel, great software.



    Vy 73


    Holger ‚Geri‘, DK8KW

    Hallo zusammen,


    im Augenblick werden bei ebay aus Thailand für 14,- US$ (allerdings plus 24.- US$ shipping) „Norsat 2500 2.4 ghz to 144mhz Satellite Down Converter“ angeboten. Ich habe mir vor 3 Wochen einen bestellt, er ist vorgestern gekommen.


    Der Konverter macht einen sehr guten Eindruck und ist meiner Meinung nach den Preis plus Porto wert. Er setzt 2400,00 MHz auf 122.00 MHz um, ist also ideal geeignet als Erweiterung für bestehende SDR-Empfänger. Es finden sich im Internet relativ einfache Umbauanleitungen aus AO-40-Zeiten um den Empfänger im Amateurfunkband empfindlicher zu bekommen (Teflon-Klebeband auf das Bandfilter kleben). Für meine Zwecke reicht die Empfindlichkeit aus, ich kann damit mein eigenes Signal abhören und mit dem RSP1A eine einfache Spektralanalyse durchführen. Mit einer Kombination von Dämpfungsgliedern und Kopplern sollte sogar eine (relative) Leistungsmessung möglich sein.


    Short English-version: have a look on ebay for „Norsat 2500 2.4 ghz to 144mhz Satellite Down Converter“, sold from someone from Thailand. Converts from 2400,00 MHz to 122.00 MHz. Cost is 16 US$ plus 24 US$ shipping. In my humble opinion very good value for money.


    Vy 73


    Holger, DK8KW





    Hello Matthias,


    Your measurements and assumptions seem plausible to me.


    I am using an Octagon LNB in an 85cm offset dish and also SDR console as software.


    Today I measured the following data:


    CW beacon signal strength: -52,0 dBm

    Average noise: -84,4 dBm,


    so the SNR was 32,4 dBm today.


    My own signal (1 Watt output into a 1 Meter prime-focus dish, fed with a 5 1/4 turn helical) has 28 dBm (signal strength 56,3 dBm), which seems plausible, too.



    Best 73


    Holger ‘Geri’, DK8KW