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What is the Maximum Range I can Get?

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  • What is the Maximum Range I can Get?

    The Maximum Range achievable at any location depends on
    (1) Curvature of earth
    (2) The terrain around that location. Terrain plays a very important role as hills & changes in ground level will restrict maximum range.

    This is due to the fact that propagation of radio waves in GHz/Microwave range is line of sight. The range is therefore limited by curvature of earth, and is about 250 nautical miles / 450 km for an ideal condition of perfectly level terrain. Hills & rise in ground levels further restrict maximum range to less than 250 nautical miles / 450 km.

    In order to determine what maximum possible range you can get at your location, follow the steps below:
    (1) Visit the site
    (2) Select tab "new panorama"
    (3) Enter your latitude and longitude
    (4) Enter your elevation (=enter elevation of your antenna)
    (5) Enter title
    (6) Hit "submit request" button
    (7) Wait and view sponsor's advertisement while panorama is generated
    (8) When panorama is generated, scroll down to map, and click "up in the air" tab on top right of map.
    (9) Zoom-out the map till you see two circular curves in blue & yellow colors, showing maximum distance of aircrafts at 10,000 feet & 30,000 feet elevation.
    (10) Below the map you will see text boxes light yellow & light blue with default aircraft heights 10,000 feet & 30,000 feet. Change these to suite your requirements, and press "Enter" button. The two curves will modify to new height figures you have entered. I recommend to use 10,000 & 45,000 feet, as normally commercial flights are 45,000 feet & below.

    The layers of air cause refraction of radio waves, and radio line of sight may extend beyond optical line of sight by as much as 50 to 100 nautical miles. Your maximum possible range will therefore be about 50 nautical miles more than the maximum possible range shown by the curves you got from site.

    To achieve your maximum possible range, your antenna should be installed at a height where it is above trees & houses surrounding it, and can "see" the horizon.

    Last edited by abcd567; 2016-02-27, 18:21.

  • #2
    Sticky thread....
    For official support use Contact Form


    • #3
      Thanks Amper!


      • #4
        Regarding that question the answer should be easy:
        look at
        Nearly nobody cracks the 325 miles, almost everybody in the top ten is pretty exactly in that range.
        So if you are around 300 miles, relax and enjoy your station.


        • #5
          Both the sites below give maximum range in Nautical Miles.

          325 Nautical Miles = 374 Miles = 602 kilometers

          FR24-Sharer List.PNG


          • #6
            bookmarked this link.... tnx
            de WA4CHQ/qrp 99% cw since 1972. Linux using SLACKWARE since 2000


            • #7
              I agree but this morning I see this most unusual effect overnight :-
              ADS-B range.JPG
              Must be due to the large high pressure currently over Western Europe:-
              My usual maximum range from Northern England hovers between 260 and 270 nautical miles with just the odd few into the 300s
              My average range is limited by the high ground to the west, limiting me in that direction to around 155 Nm



              • #8
                Directional Antenna for extended range

                Does anyone have experience with directional antennas to extend the range a bit further? I though of a 15dB or 20dB Yagi or other type of directional antenna. I'd like to build one. But it looks like the current systems have such a good sensivity and already reach far beyond the horizon.