Announcement

Collapse
No announcement yet.

How do I adjust the gain the right way

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • How do I adjust the gain the right way

    So today I've switched from the generic USB dongle to prostick plus with fa filter and wow it made a huge difference, I've already turned down the gain to 40 as it was mentioned I would have to turn it down.

    My question is how do I determine exactly where the gain should be? I tried to search but the only thing I find are for piaware users that have a formula they get with numbers from their logs which apparently I can't access in the fr24 install.

    Right now, if it means anything, only about half the aircrafts tracked are uploaded according to the 8754 status page, and I have the gain set for 40

  • #2
    If you install dump1090-mutability, it has the capability to show message rate. You can also install prerformance graphs, so that you can monitor graphically.

    However installation of dump1090-mutability on Pi24 image is not straight forward, and needs workarounds.

    If you write on microSD card, the Respbian Jessie Lite image (download from http://raspberrypi.org/downloads/raspbian ), you can then install dump1090-mutability and FR24 data feeder without any complication and workaround.

    Please see this thread:

    How to Install dump1090-mutability_1.15~dev on RPi



    .
    Last edited by abcd567; 2017-07-07, 21:52.

    Comment


    • #3
      I'm not sure what happened to my reply

      Thank you for that answer, I was trying to avoid doing that as I have no experience in it at all but I guess I'll have to try it after all

      Do I reuse the same sharing code I already received from fr24?

      Thank you again

      Comment


      • #4
        Originally posted by 71sbeetle View Post
        I'm not sure what happened to my reply

        Thank you for that answer, I was trying to avoid doing that as I have no experience in it at all but I guess I'll have to try it after all
        Linux in the begining looks very difficult, but as you go through it, becomes easy.

        In order to avoid typing mistakes, copy-paste commands from the thread, one command at a time.

        Take care not to omit any step. To check what was your last step, press arrow-up key, then after checking, press arrow-down key to go back to command prompt.

        Note:
        (1) After writing Raspbian Jessie to your microSD card, dont remove it from your desktop/laptop. First in File Explorer, click the drive letter of microSD card to open the folder. Right click in this folder and create a blank text file named SSH or SSH.txt. Without this file, SSH will not be enabled. After createing this file, remove microSD card from your desktop/laptop, insert into Pi, and power up. Now you can SSH into Pi from your desktop/laptop. You will need to install SSH software called PuTTY if using Windows computer. In Mac, the command console is capable to SSH, and you dont need to install any SSH software

        (2) To make things simpler, omit the optional item "(8) Add Terrain Limit Rings". You can add these later if you want.

        Do I reuse the same sharing code I already received from fr24?
        YES. Same email and same sharing code.
        Last edited by abcd567; 2017-07-07, 23:10.

        Comment


        • #5
          Originally posted by abcd567 View Post
          Linux in the begining looks very difficult, but as you go through it, becomes easy.

          In order to avoid typing mistakes, copy-paste commands from the thread, one command at a time.

          Take care not to omit any step. To check what was your last step, press arrow-up key, then after checking, press arrow-down key to go back to command prompt.

          Note:
          To make things simpler, omit the optional item "(8) Add Terrain Limit Rings". You can add these later if you want.


          YES. Same email and same sharing code.
          Excellent thank you, I am copying the jessie lite img to a 2gb micro sd card right now
          I am assuming I can access the Pi 3 via PuTTY like I currently can with the fr24 image?

          Comment


          • #6
            Alright, got it all done and running thank you so much for the help, now I need to find out how to graph it and I need to tune the gain
            Again thank you!

            Comment


            • #7
              As you have installed dump1090-mutability, you can now run a gain optimization sript to help you decide the value of gain. See this post/thread:



              .

              Comment


              • #8
                Originally posted by abcd567 View Post
                As you have installed dump1090-mutability, you can now run a gain optimization sript to help you decide the value of gain. See this post/thread:



                .
                Wow very interesting thank you!
                It's running 5 tests of 15 seconds right now, we will see

                Comment


                • #9
                  Credit for this gain optimization script goes to its original author BartJr. (http://discussions.flightaware.com/p...4.html#p192634).

                  Later some enhancements were done by lignumaqua and others, but the script is basically same as written by BartJr.

                  .
                  Last edited by abcd567; 2017-07-08, 02:53.

                  Comment


                  • #10
                    Nifty little "automatic" gain finder.

                    I think I will need to rerun it with times longer than 15 seconds, in 5 tests it found as low as 36.4 and as high as 44.5 were optimal
                    I reset it to 40.2 for now until I can run a longer testing period

                    Comment


                    • #11
                      With commercial antennas like jetvison or flightaware, installed on roof or mast, people have reported using gain as low as 25 dB.

                      I use 30 and 35 for my two systems.

                      Comment


                      • #12
                        Originally posted by abcd567 View Post
                        With commercial antennas like jetvison or flightaware, installed on roof or mast, people have reported using gain as low as 25 dB.

                        I use 30 and 35 for my two systems.
                        Ok good to know.
                        I currently have my gain at 36.4 for the last 24 hours I will have to check how it did, but I have gotten almost double the aircrafts seen so far, and went from about 25,000 positions reported to nearly 120,000!!!
                        I need to run the gain script again I didn't have the time to do it yet. Do I really need to run it 10 times at 45 seconds for each gain?
                        I was looking at the thread you had sent me, it looks like there is a way to change color of distance rings I may do alternating colors on mine!

                        Comment

                        Working...
                        X