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  • Originally posted by Amper View Post
    Next thing on my wish list
    See my receiver's picture below:
    Grundig Satellit 750, purchased 4 years ago.
    Grundig Satellit 750.jpg
    Last edited by abcd567; 2013-12-16, 05:51.

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    • Installed my Antenna outside this afternoon but unfortunately my signal and aircraft count has dropped to barely nothing. What did happen at one stage during the install was i pulled the antenna cable and one of the joints came apart. I redid the joint but maybe i wasn't careful enough and the contacts were not made.The other thing that i had to do was add a coax cable joiner as my cable wasn't long enough. In adsbscope i'm getting a quality level of 40% and am getting some aircraft but only ones very close. Would a bad joint cause a drop in signal or a complete loss? Also would a cable joiner cause any issues. It looks like another round of up and down the ladder tomorrow.

      Mike

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      • Originally posted by mickopla View Post
        Installed my Antenna outside this afternoon but unfortunately my signal and aircraft count has dropped to barely nothing. What did happen at one stage during the install was i pulled the antenna cable and one of the joints came apart. I redid the joint but maybe i wasn't careful enough and the contacts were not made.The other thing that i had to do was add a coax cable joiner as my cable wasn't long enough. In adsbscope i'm getting a quality level of 40% and am getting some aircraft but only ones very close. Would a bad joint cause a drop in signal or a complete loss? Also would a cable joiner cause any issues. It looks like another round of up and down the ladder tomorrow.

        Mike
        Mike,

        From my vast ( not much) experience it could be a short or open circuit at one of those points you mention. It's surprising how much you can pick up with just the antenna cable itself, but vastly improve reception when all is well all the way to the antenna. Check those couple of things you mention, it could be either (or both). Hope you have a multimeter as it helps for checking for faults in cable. You may have nothing from the antenna at all.

        Just dont get caught like I did with the antenna. Some have a DC bridge across the thing to help assist with it's operation (one of the technical experts could likely explain this much better than I if needed). In other words, you can test the antenna with a multimeter on DC and think there's a short but it's meant to be there (as I said on SOME antennas only).

        Get those legs working mate, it's all part of the 'fun'
        .

        Regards,
        Gregg
        Last edited by fungus; 2013-12-16, 21:18.
        YSSY2/T-YSSY4 [SBS-1 Basestation w/- SSE-1090 SJ Mk2 Antenna (Thanks Delcomp) ] [Uniden UBCD996T w/- 16 element Wideband Discone VHF/UHF Antenna, and tuned 108MHz-137MHz Airband Antenna] [Trialing a home-brew 1090MHz collinear antenna]

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        • Originally posted by mickopla View Post
          . Would a bad joint cause a drop in signal or a complete loss? Also would a cable joiner cause any issues. It looks like another round of up and down the ladder tomorrow.

          Mike
          You can have all kinds of things go wrong with connectors. Open connection, shorted connection, poor 'resistive' connection, and outdoors it's always a problem when you have water intrusion. It's best to run a solid cable with no joints when ever possible. .
          www.ADS-B.ca

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          • Fellow ADS-B chaps,
            I have been AFK for a while and I see a lot has happened on the antenna side of things. Since my previous problem with my setup, its about time to build a new antenna to compensate for the additional cable loss I now have, and the smaller coverage area. What is the current best design you gents have discovered?

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            • Originally posted by fungus View Post
              Mike,
              .........Just dont get caught like I did with the antenna. Some have a DC bridge across the thing to help assist with it's operation .....
              Regards,
              Gregg
              Originally posted by mickopla View Post
              Installed my Antenna outside this afternoon but unfortunately my signal and aircraft count has dropped to barely nothing.........
              I remember Mike mentioning an antenna with a whip at top without a short.
              In this case if the antenna cable is disconnected from amplifier & continuity between core & shield is tested, it should show "no continuity". If it shows continuity, it means a short somewhere in antenna elements joint or in cable joint.



              Sent from my N762 using Tapatalk 2
              Last edited by abcd567; 2013-12-16, 21:48.

              Comment


              • Originally posted by abcd567 View Post
                I remember Mike mentioning an antenna with a whip at top without a short.
                In this case if the antenna cable is disconnected from amplifier & continuity between core & shield is tested, it should show "no continuity". If it shows continuity, it means a short somewhere in antenna elements joint or in cable joint.



                Sent from my N762 using Tapatalk 2

                How exactly do i do this? Red to braid and black to center? What am i looking for on the multimeter? I'm just learning how to use a multimeter so forgive me for the questions.

                Mike

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                • Set it on the resistance test setting - thats the one that shows a low reading when you connect the probes together.
                  While you are making the coco you want a high reading (like probes not connected together) while you are doing the construction - this is one probe connected to the core and one to the braid as each stage is added..
                  I used non mettalic duct tape to hold my coco sections together - the vinyl tape I had was just too frail to take any strain.

                  Sent from my GT-P5110 using Tapatalk

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                  • Originally posted by peterhr View Post
                    Set it on the resistance test setting - thats the one that shows a low reading when you connect the probes together.
                    While you are making the coco you want a high reading (like probes not connected together) while you are doing the construction - this is one probe connected to the core and one to the braid as each stage is added..
                    I used non mettalic duct tape to hold my coco sections together - the vinyl tape I had was just too frail to take any strain.

                    Sent from my GT-P5110 using Tapatalk
                    Seems straight forward enough. I made another CoCo this evening which i will use for testing tomorrow in order eliminate potential problems with connections on power inserter and amp.

                    Mike
                    Last edited by mickopla; 2013-12-16, 23:42. Reason: grammar errors

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                    • Originally posted by mickopla View Post
                      How exactly do i do this? Red to braid and black to center? What am i looking for on the multimeter? I'm just learning how to use a multimeter so forgive me for the questions.

                      Mike
                      Mike:
                      (1) what type of multimeter you have? Digital or analog (moving needle type).
                      (2) Does you meter have a continuity check setting (buzzer/light)? Most multimeters have it, but some lack it.
                      Last edited by abcd567; 2013-12-17, 15:48.

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                      • Originally posted by HermanZA View Post
                        Fellow ADS-B chaps,
                        I have been AFK for a while and I see a lot has happened on the antenna side of things. Since my previous problem with my setup, its about time to build a new antenna to compensate for the additional cable loss I now have, and the smaller coverage area. What is the current best design you gents have discovered?
                        CoCo with top element 1/4 wave, core shorted to braid at top, has proved best for my imstallation. Thanks to "1090MHz" for the design tip.

                        Adding an amplifier substantially improved range.

                        Adding a decoupling sleeve/balun may improve further, but I postponed it's construction & testing due to personal preoccupation & severe weather.

                        Sent from my N762 using Tapatalk 2
                        Last edited by abcd567; 2013-12-17, 04:25.

                        Comment


                        • Originally posted by mickopla View Post
                          How exactly do i do this? Red to braid and black to center? What am i looking for on the multimeter? I'm just learning how to use a multimeter so forgive me for the questions.

                          Mike
                          Mike, visit this page which shows how to test continuity (short) by a multimeter:

                          http://www.ladyada.net/library/metertut/continuity.html

                          continuity-test-1.jpg

                          continuity-test-2.jpg

                          continuity-test-3.jpg
                          Last edited by abcd567; 2013-12-17, 07:31.

                          Comment


                          • Originally posted by abcd567 View Post
                            Mike, visit this page which shows how to test continuity (short) by a multimeter:

                            http://www.ladyada.net/library/metertut/continuity.html

                            [ATTACH=CONFIG]3073[/ATTACH]

                            [ATTACH=CONFIG]3074[/ATTACH]

                            [ATTACH=CONFIG]3075[/ATTACH]
                            Thanks abcd567 for the link. Last night i made a 3 element CoCo for testing. I'm tempted to use this instead of the 9 element one i was using previously. What would the main differences be between using 3 element and 9?

                            Mike

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                            • Originally posted by mickopla View Post
                              Thanks abcd567 for the link. Last night i made a 3 element CoCo for testing. I'm tempted to use this instead of the 9 element one i was using previously. What would the main differences be between using 3 element and 9?

                              Mike
                              Theoritically:
                              Gain of 4 element (or 3-1/2 element) = 5dBi
                              Gain of 8 element (or 7-1/2 element) = 8 dBi

                              Advantage in using 8 element instead of 4 elements is 3dB extra gain (8dB-5dB) , but you already have extra gain of 20dB from your Amplifier.

                              Increasing number of elements increases gain for distance planes, but reduces gain for nearby planes. See image below.
                              Franklin-Co-Linear-Antenna-Directivity.gif
                              Last edited by abcd567; 2013-12-17, 15:53.

                              Comment


                              • Originally posted by mickopla View Post
                                Thanks abcd567 for the link. Last night i made a 3 element CoCo for testing. I'm tempted to use this instead of the 9 element one i was using previously. What would the main differences be between using 3 element and 9?

                                Mike
                                Apparently 9 element antenna should give a better result than 3 element antenna.
                                The best way to find out is to try both the 3 element & 9 element antennas, and compare results.

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