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  • Originally posted by YWYY View Post
    Hi , I spaced the beams 1.5 wavelengths - thats 275mm x 1.5 = 413mm
    The feeding harness is made with multiples of 1/4 wave ............
    Thanks for the detailed information sbout hook-up arrangement/phasing harness.

    .........Initial tests show an improved gain over the single beam
    [ATTACH=CONFIG]5232[/ATTACH]
    Mike
    308 nm max coverage! Great!

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    • My First Spider

      DSC03467-R.jpg . DSC03469-R.JPG . DSC03471-R.JPG . DSC03475-R2.jpg


      One Hour Trial Run- No amplifier, 5 meters/15 feet cheap quality RG6 coax between Spider Antenna & USB Receiver.
      Max range 225 nm (Range Rings are 50nm apart)
      Spider Antenna 1 hr trial run -Dec21, 2014.jpg
      Last edited by abcd567; 2014-12-22, 02:15.

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      • Spider Main Parts List:

        (1) Connector UHF SO239 solder type, panel mount 4-hole 25mm flange:
        http://www.ebay.com/itm/Connector-SO...-/271456478469
        SO-239.jpg

        (2) UHF male plug PL-259 to F female Connector:
        http://www.ebay.com/itm/F-female-jac...-/171488687544
        PL-259 to F Female.JPG

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        • Comparison of Spider with Cantenna
          No amplifier, 5 meters/15 feet cheap quality RG6 coax between Antenna & USB Receiver - for both Spider & Cantenna.

          Spider Antenna 4 hrs trial run - maximum range 225nm (range rings are 50nm apart)
          DSC03471-R.jpg . Spider Antenna 4 hr trial run -Dec21, 2014.jpg


          Cantenna 3 hrs trial run - maximum range 225nm (range rings are 50nm apart)
          DSC03477-R.jpg . Cantenna 3 hr trial run -Dec21, 2014.jpg

          Note: Spider's coverage screenshot was taken at 9:30 in evening, when number of planes is large, whereas cantenna's coverage screenshot was taken half an hour after midnight, when number of planes drops considerably.
          Last edited by abcd567; 2014-12-22, 14:10.

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          • I've overlaid the Heywhatsthat range from my location with the range plot from Virtual Radar Server. The blue line is 40,000' and the Orange is 30,000' This is with my 24 element CoCo. Doesn't look like I can get much better.
            24 element CoCo range.jpg
            T-EGUB1

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            • Originally posted by trigger View Post
              I've overlaid the Heywhatsthat range from my location with the range plot from Virtual Radar Server. The blue line is 40,000' and the Orange is 30,000' This is with my 24 element CoCo. Doesn't look like I can get much better.
              [ATTACH=CONFIG]5250[/ATTACH]
              Once you have reached line of sight limit set by curvature of earth, your terrain & antenna height, you cannot increase range by increasing gain of antenna. The only way is to increase height of antenna, but not in feet, rather in hundreds of feet. Cant afford an antenna mast several hundred feet high.

              Just for fun, try heywhatsthat.com again and instead of your antenna's actual height (20 or 30 feet?), enter 100 feet. You will see some increase in range, but not much. Now enter 2000 feet as your antenna's height. I am sure it will cover a latge part of UK, Spain & France.

              Alternatively tie your antenna to a helium filled baloon & let it float at 2000 feet above ground and let VRS plot the coverage

              By the way, you have done a good job in Photoshop to overlay the two plots.
              Last edited by abcd567; 2014-12-23, 12:50.

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              • Amazing! How can they sell at such a low price, and that with free shipping from china to any place in the world!!!!

                Chinese in line amplifier.jpg

                Canadian $3.66 = US $3.14 = € 2.58 + free international shipping from china

                http://www.ebay.com/itm/221636917204

                .

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                • Originally posted by abcd567 View Post
                  Amazing! How can they sell at such a low price, and that with free shipping from china to any place in the world!!!!
                  http://www.ebay.com/itm/221636917204[/b]
                  .
                  but not the UK
                  T-EGUB1

                  Comment


                  • Originally posted by abcd567 View Post
                    Amazing! How can they sell at such a low price, and that with free shipping from china to any place in the world!!!!
                    http://www.ebay.com/itm/221636917204[/b]
                    .
                    I tested the inline amplifier with two power injectors, but it didn't work. There was no aircraft detected.

                    The left side is connected to an 8-elements coco, the power injector on the right is connected to the USB receiver dongle on Raspberry Pi. The power injector is connected to 16.8V power supply (measured with a multimeter).

                    There's voltage measured on the left end (ANT) of the amplifier, but no voltage measured on the left end (HF) of the dc blocking that connects to the antenna.

                    Is the setup correct?

                    amplifier-power-inserter.jpg

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                    • Hi bezeefly, looks OK to me. The left hand DC blocker is doing its job by stopping the volts going up the antenna. For a coco, this DC blocker is used as insurance in case you have a short in the coco which would fry the amp.

                      Do you see aircraft without the amp and blockers?
                      T-EGUB1

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                      • Hi trigger, I can see aircrafts without the amp and blockers. The best distance I manage to track is about 290 KM.

                        When I installed the amp and blockers, the aircraft count dropped to zero. Removing the left hand DC blocker and connected the antenna to the amp didn't work too.

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                        • Comment


                          • Thank you ABCD. Seasons' Greetings to you and to the rest of our little "antenna gang" here.

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                            • Originally posted by bezeefly View Post
                              Hi trigger, I can see aircrafts without the amp and blockers. The best distance I manage to track is about 290 KM.

                              When I installed the amp and blockers, the aircraft count dropped to zero. Removing the left hand DC blocker and connected the antenna to the amp didn't work too.
                              Check the DC polarity. The center wire of coax should be positive (+) and shield/braid negative (-).

                              Most probaly you have connected power adapter's negative (-) wire to coax's core & positive wire to cox's shield braid. Check polarity b a voltmeter or multimeter.

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                              • The DC polarity is correct, where the centre wire of coax is connected to the power adapter's positive (+).

                                The description of the amp stated:

                                This is a high quality inline amplifier with up to 20dB gain. This amplifier is DC passive. For long satellite cable runs and improvement of satellite signal strength. No need for separate power supply.

                                Probably the amp doesn't work at all. I've ordered another model of amp to test it.

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