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  • Originally posted by majo View Post
    ...........
    Do you have an idea or simple way to detect and quantify RF noise at a given location?
    There is no easy way to find RF noise except by using costly test equipment.

    Best option is to buy an Orange ProStick and an external Filter.

    First set the gain at 38 dB, and try Orange ProStick alone. Next at same gain setting add the external Filter and try again.

    Compare the two results. It will give you an indication if adding a filter is benefitial or not.

    After finding which is better (with or without filter) adopt that setup. Now set gain at 49.6 dB, then drop down in steps of 3 dB and watching where you get maximum message rate. Generally people get best between 30 dB and 45 dB.

    Comment


    • @abcd567:
      Thank you!
      According to your advice I just changed the gain setting. Let`s wait and see...
      BTW: Are the FA-Sticks more stable concerning the ppm-value than the ordinary DVBT-sticks or is it worth to do a x-check with sdr for possible adjustment?

      Comment


      • @majo
        I never bothered about ppm value of any type of stick. Always left ppm at its default setting whatever it was.

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        • @abcd567
          That is interesting!

          And what is your experience concerning gain: Figure out best setting for actual environment or use auto gain (-10)?

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          • @majo
            What is best varies greatly with location. Try all possibilities.

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            • I want to purchase a low cost instrument for swr /impedance/frequency sweep of 1090 mhz DIY antennas.
              I am considering to buy this one for $184 + free shipping. Has anyone tried it?

              New 140MHz~2.7GHz UV RF Vector Impedance ANT SWR Antenna Analyzer Meter Tester





              Operating Frequency :140MHz ~ 2700MHz
              Frequency Step :1kHz
              monitor dispaly :2.4-inch TFT Resolution 320 240 (QVGA)
              battery capacity: 2000mAH (7.4Wh)
              Power consumption : <1.5W
              Charge Current: 400mA
              Charging Interface: USB (only temporarily as the charging interface, data transmission not yet open)
              Automatic shut-down( You can set open, 5 minutes to 60 minutes Optional)
              Measurement parameters:
              impedance : 0.1Ω ~ 1000Ω (impedance absolute value)
              SWR: 1.000 to 65
              s11 (dB): 0dB ~ -60dB
              Resolution
              impedance : <Impedance absolute value 3% 0.1Ω (Z less than 200Ω, <1.5GHz)
              SWR : <Valid reading 10% 0.1
              s11(DB / ): 0.1 dB / 5 (0dB ~ -10dB)
              1 dB / 10 (-10dB ~ -20dB)
              5dB / 20 (-20dB ~ -40dB)
              Directionality :<35dB (140MHz ~ 2GHz after calibration), <30dB (2GHz ~ 2.7GHz)
              Scan Points: 280
              Output Level: -18dBm
              Operating temperature: 0 ℃ ~ 40 ℃

              Comment


              • I went out and bought a ads 1090mhz antenna from flight aware. $55 what a difference even just inside my window four floors up. This will be going on the roof shortly 7 floors up. I will be testing out cables for best reception. Jimm

                Comment


                • @ShoeGolf
                  After you finish fixing your antenna on roof, you may need an amplifier if coax is too long.

                  You can try Flightaware ProStick Plus (Blue) which has a built-in amplifier and built-in filter. In most cases, the built-in filter is enough and an external filter is not required. However, if the RF noise at your location is strong, you may need an external filter also.

                  Comment


                  • at present I am running the prostick plus the coax run will be 30ft which I will be switching to will be Rg6 geared for 1 to 2ghz the

                    Comment


                    • Originally posted by ShoeGolf View Post
                      at present I am running the prostick plus the coax run will be 30ft which I will be switching to will be Rg6 geared for 1 to 2ghz the
                      RG6 attenuation is 6.7 dB / 100 ft (22 dB / 100 meters).
                      For 30 ft, attenuation will be about 2 dB.
                      The gain of ProStick Plus built-in amplifier is, I think, 15 dB, which can easily cover the coax attenuation.

                      One of the North Atlantic Track passes over/near Helifax. You will be seeing lot of air traffic to/from Europe
                      Last edited by abcd567; 2017-01-01, 02:13.

                      Comment


                      • I don't think I've seen this mentioned, so, let me point it out ...

                        For folks building antennas and looking for a quick comparison - start dump1090 in interactive mode, look for the "signal" column in the table, this displays what is known as RSSI or Received Signal Strength Indication - consider it an uncalibrated signal strength meter - you can use it to compare the strength of two signals received by the same hardware, very useful for quick comparisons, or tweaking/tuning/trimming antennas.

                        Comment


                        • Hi fordem!

                          Could you please explain where and how to enter that "dump 1090 interactive mode"?

                          Thanks, majo

                          Comment


                          • Find the instructions you used to install dump1090 - they should tell you how to start it in interactive mode, and which directory you should be in.

                            Typically it will be something like

                            Code:
                            ./dump1090 --interactive
                            dump1090 has many options available, and these options are executed by including the "switch" when calling the program, if calling it from a command line prompt, or, if calling it from a script, the script can be edited to include the "switch" - at the command line type dump1090 --help to see the available options, it can be run with multiple options by entering the options on the same line, for example, if you wanted both interactive mode and the integrated web server at the same time.

                            Code:
                            ./dump1090 --net --interactive

                            Comment


                            • Test Results for Cantenna, Using Antenna Analyzer N1201SA.


                              Test Setup




                              R, X, VSWR, S11




                              VSWR vs Frequency Sweep Plot. Marker at 1090 Mhz

                              Comment


                              • You kept the dielectric on the center conductor. What correction coefficient did you use?

                                Sent from my Pixel using Tapatalk

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