LNB POLARIZATION PROBLEM?

  • Hey,


    only uplink is circulair not the down link.


    Wb=Horizontal


    NB= Vertical.....


    "My goal is to try to get the signal from a satellite"....with the helix you DONT receive the satellite dr friend...

    so you dont have to modify the lnb if you want rx with a sdr stick ore somthing like that...i dont know your rx so pls tell use....howe will you receive the satellite,


    greetings


    Luc ON7KEC

  • Hi,
    please explain a bit more detailed what you want to accomplish.
    The second diagram you posted where you want to connect a DC power supply and an oscilloscope via a PL-Tee to an amplifier does not make any sense ...

    Kind regards

    Matthias

  • But it is a satellite where the downlink is RHCP.

    If this discussion does not apply QO-100, then it should be moved in a general forum.


    If the "satellite" has a RHCP polarization, then the helix must be also RHCP. A helix-feeder mounted at a dish must be LHCP because the wave is reflected and the polarization inverted. A TV LNB has only vertical or horizontal polarization.


    Hope this helps.

  • If this discussion does not apply QO-100, then it should be moved in a general forum.


    If the "satellite" has a RHCP polarization, then the helix must be also RHCP. A helix-feeder mounted at a dish must be LHCP because the wave is reflected and the polarization inverted. A TV LNB has only vertical or horizontal polarization.


    Hope this helps.

    Yeah, sorry. I ended up posting here because I was talking about LNB ;)


    Yes Yes. RHCP. My question is, the LNB seller said to me, "Good afternoon Luis, you will need to do the conversion first. Typically in the feed assembly or separate polarizer. The LNB reads horizontal."


    I usually do this conversion when I work with waveguides. This time is something new for me. I'm just using an SMA cable connecting my antenna and the LNB, as shown in the diagram.


    Thanks

  • Luis,

    this makes no sense.

    A LNB which is connected to an antenne using a coaxial cable is not sensitive to any polarization.

    It just takes the signals which come from the antenna, whichever polarization the antenna may have.

    If you like we can take this discussion offline as it does not fit at all in this forum.

    You can find my email adress on my website.

    Regards

    Matthias

    http://www.dd1us.de