Antenna

  • Choice of Antenna

    Antenna


    Uplink + Downlink (TX/RX) with Dish


    To receive QO-100 you need at least an 85 cm dish and preferably 1 m or more for DATV and on the edge of the footprint. Learn how to aim your dish at the Es'hail-2 satellite on DishPointer. First select "25.9E ES" on the right and then "Your location". Then draw the direction line exactly to your location. Here you will also find the skew angle for adjusting your LNB. Now you should be able to easily align your dish and receive the first PSK beacon signals. You can now make fine adjustments using the beacon signal (Audio sample).


    Note: Do not look for the footprint of Es'hail-2, this is different from the QO-100 transponder. For Es'hail-2, you'll just find spot beams for its TV channels.


    For the uplink, choose a patch antenna or a helix (LHCP) as the feeder. Kurt, DJ0ABR, wrote an article about building a helix feeder yourself. And here you will find an article by Matthias, DD1US, about his construction with dual band feed and LNB.


    Uplink with other antennas

    A right-hand circular (RHCP) helix antenna can also be used via the NB transponder. However, this is not recommended. Such a Helix antenna has a lower gain that a medium sized parabolic dish. Thus, more transmit power is needed and this results in combination with the broader beam-width and the lower front-back-ratio to unnecessary high radiation in the vicinity of the antenna. It is also possible to use a 2.4 GHz WiFi grid antenna. Also this is not very efficient as they are usually linear polarized and thus exhibit a loss of 3 dB compared to right-hand circular polarization.


    Helix.png  wifi grid antenna small.jpg


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