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Thread: pi24 and reduced coverage

  1. #11
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    Hi, recently my pi build has been automatically upgraded to software Linux/generic/static_armel/1.0.23-7

    However I am noticing a quite reduced range... in the last few weeks my max was around 349Nm.. in these few days it is only 260Nm... I checked my hardware etc and everything is ok... antenna still pointing vertical (checked with spirit level etc)

    Did someone noticed this lately ?

  2. #12
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    Any updates?

  3. #13
    Purser
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    Mine auto updated and the coverage seems about the same... (not sure that's helpful?)

  4. #14
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    Quote Originally Posted by lodervsm View Post
    Hi, recently my pi build has been automatically upgraded to software Linux/generic/static_armel/1.0.23-7

    However I am noticing a quite reduced range... in the last few weeks my max was around 349Nm.. in these few days it is only 260Nm... I checked my hardware etc and everything is ok... antenna still pointing vertical (checked with spirit level etc)

    Did someone noticed this lately ?
    fr24feed and 1090 mutability dont play nice together
    setting gain to 49 which is max, and is reported by fr24feed, is actually false
    I fixed my problem by /etc/fr24feed.ini adding procargs="--gain -10"
    this was suggested by someone in Germany who had similar problem and fixed his range, as it has fixed mine, now i'm back to normal, avg of 90nm all directions and out to 150nm northeast, though fr24 seems to think my max range is only 80nm, another service I feed reports 151nm, which matches my 150nm range plot

  5. #15
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    Hi, I reduced the gain to 37.2 and seems to be working normally.. or even better. Seems that wind direction affects receiving range in my position. South winds seems to improve my receiving distance.

  6. #16
    Team FR24
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    Pi24 image has been updated and should support 3b+ now. Also, by default its starts with "-- gain -10" and no max as the previous version did. As Oblivion, abcd567 and Ressy mentioned/showed previously that if you see any changes in the range, you can play around with gain settings to see if that makes things better.
    --

  7. #17
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    Amended my 3b+ warnings out again.

    Abcd567 will no doubt do similar.

    Sent from my XT1092 using Tapatalk
    Posts not to be taken as official support representation - Just a helpful uploader who tinkers

  8. #18
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    Quote Originally Posted by Khan View Post
    ...you can play around with gain settings to see if that makes things better.
    Yes, for me "-10" is almost the worst option! Averaging each gain twice over 90 seconds and then taking the percentage of the highest result so it's easier to plot everything on the same graph I get:

    d-table.png

    d-graph.png

    I thought I'd read somewhere that the -10 / AGC option was designed to work at TV frequencies rather than 1090MHz?

  9. #19
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    Quote Originally Posted by elljay View Post
    I thought I'd read somewhere that the -10 / AGC option was designed to work at TV frequencies rather than 1090MHz?
    That is right. The dongle is designed for TV, and NOT for ADSB ( DVBT = Digital Video Broadcast, Terestrial).


    Please see following two posts on page #6 of the thread How to Install dump1090-mutability_1.15~dev on RPi


    (1) Dump1090-mutability: About gain -10


    (2) ABOUT AGC


    .
    Last edited by abcd567; 2018-10-29 at 16:19.

  10. #20
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    Quote Originally Posted by elljay View Post
    Yes, for me "-10" is almost the worst option! Averaging each gain twice over 90 seconds and then taking the percentage of the highest result so it's easier to plot everything on the same graph I get:

    d-table.png

    d-graph.png

    I thought I'd read somewhere that the -10 / AGC option was designed to work at TV frequencies rather than 1090MHz?
    The same dongle performs differently, on linux pc's, 2 of them, plus a linux laptop, all different brands, work best on max gain, but rpi works best on -10 unline teh real pc's. Something in the rpi I guess.

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