Announcement

Collapse
No announcement yet.

Few position reports ?!?

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

  • wiedehopf
    replied
    The dongle is not damaged, no worries!

    I'm just saying numbers fluctuate with ADS-B with weather.
    And noise fluctuates much more than you might think. For example imagine a LTE (mobile data) receive/send mast near you. No one is using it. So most of the time it's not sending and saving power. Your reception when only few people are using LTE will be good.
    On the weekend reception will be bad, because maybe more people are using it and it is sending all the time.

    All i was saying depending on the TYPE of dongle you are using will change the reaction to noise.
    If the dongle has an amplifier in it like the yelllow flightaware it might react much more to certain noise (bad reception) than the jetvision dongle which has no internal amplifier.

    Hope that make some sense.

    Leave a comment:


  • Talle
    replied
    Hmm, do you say that the dongle gets tired of overloading over time ? Is this permanent "damage" or will it get back to normal after some rest ?

    Leave a comment:


  • wiedehopf
    replied
    Originally posted by Talle View Post
    Changed the dongle at about 0930Z. Lets see if it will start to fall again after a few days.
    If you went from a dongle with builtin LNA to one without LNA it's not that surprising. The LNA can get more easily overloaded with noise, so if you don't have a filter in front of the LNA, not using an LNA can be better.

    Leave a comment:


  • Talle
    replied
    Skjermbilde 2019-01-28 kl. 11.28.30.png

    Changed the dongle at about 0930Z. Lets see if it will start to fall again after a few days.

    Leave a comment:


  • Talle
    replied
    And after changing dongle, instantly the "positions reported" started to rise. Hmm, strange.

    Leave a comment:


  • wiedehopf
    replied
    You may have some problem with you cable leading to your antenna, but if you got that with your A3 antenna it should be a good cable so i don't think so unless you bent it really hard.

    Be sure to weatherproof it with sealant tape to protect your nice cable.

    ADS-B reception changes with weather, so one day the signals may be more attenuated.
    Now add to that the noise staying constant or even getting more as more people are maybe using LTE because it's the weekend.
    4 days is hard to say if it is just fluctuations in traffic and weather and stuff or a trend.

    Leave a comment:


  • Talle
    replied
    Thanks for your help, will definitely have a look at the gain. It might help.

    I really don't think it is noice. Why would it then become progressively worse at the days pass by ? Also that probably sorts out the "dongle damage by static" thing, since I would then suspect the "fault" to show up suddenly, like a lightening strike, not sneaky. I think I will try the DVB-T dongle for a few days (my radarscape is only a few days away anyway) and see if there is any change.

    There is actually quit some flights north of me, but the reason for the bad reception to north is mountains. My chart (FL100 and FL300) is attached.Surgravvegen13.jpg

    Leave a comment:


  • abcd567
    replied
    Originally posted by Oblivian View Post
    You can always recheck the gain to squeeze more out (thread with how to adjust gain about somehere)
    (1) By trial & error, using RSSI as guide:
    https://forum.flightradar24.com/thre...ll=1#post82689

    (2) By optimize gain script
    https://forum.flightradar24.com/thre...ization-Script

    Leave a comment:


  • Oblivian
    replied
    Ahem...

    https://forum.flightradar24.com/showthread.php?t=11450

    (Don't always need to head off forum to the competitor for help )

    Sent from my EML-L09 using Tapatalk
    Last edited by Oblivian; 2019-01-28, 08:37.

    Leave a comment:


  • wiedehopf
    replied
    Originally posted by Talle View Post
    And today (monday) is the same. LOT of hits, but few positions, compared to other receivers in the area. Something is definitly wrong. I think I will have to try the Jetvision DVB-T stick and see if that is better. It has been snow weather the last days, so I am thinking about static can have done some damage to the flightaware stick ?
    I guess there are not many flights north of you, are there?
    The radarcape is quite a bit better at coping with mobile phone and TV signal noise. (The ModeS Beast is probably the quite a bit cheaper receiver only part that is built in to the Radarcape, but the Radarcape does have a nice GPS clock coupled into the receiver)

    The yellow Flightaware stick really needs a filter probably.
    If you can shell out the money for a radar cape and want to experiment, try a rtl-sdr dongle v3 + their 1090 MHz LNA. (The LNA has 3 filters, copes very well with noise)
    (https://www.rtl-sdr.com/new-product-...mhz-ads-b-lna/)
    Also i would probably recommend another sd-card image for the pi, you can still install FR24 and other feeders, check out this excellent guide well worth a read:
    https://discussions.flightaware.com/t/bake-a-pi/19886

    The other antenna on the roof should at most block a small portion of the sky but nothing more.

    Probably you just have LTE or other mobile phone signals messing with your reception, if you want to check the power spectrum with the dongle, that's also possible:
    https://discussions.flightaware.com/...a-filter/27833

    Good luck and i'm pretty sure you will have excellent reception with the Radarcape. (Also very good filtering)

    Leave a comment:


  • Oblivian
    replied
    You can always recheck the gain to squeeze more out (thread with how to adjust gain about somehere)

    But yes, static can zap components.


    Sent from my EML-L09 using Tapatalk

    Leave a comment:


  • Talle
    replied
    Originally posted by wiedehopf View Post
    I'm not sure what "hits" are on flightradar24 to be honest. Maybe you have a lot of noise that is wrongly decoded as preambles but the messages are garbage.

    What kind of setup of antenna / dongle are you using?
    (If you have a lot of noise and in general to improve reception a specialized LNA is very good: https://www.rtl-sdr.com/new-product-...mhz-ads-b-lna/ )

    Are you above the trees or hills of the area?
    I am using the yellow flightaware pro stick at the moment. But I have a radarscape on order. The antenna is a "A3 ADS-B antenna, mounted about 1,5M above the highest point on the house. BUT there is a dual bander (2M / 70CM) antenna about 1 meter from the ADS-B antenna which is slightly higher than the ADS-B antenna. But it has NOT been transmissions on this antenna during these days.

    And today (monday) is the same. LOT of hits, but few positions, compared to other receivers in the area. Something is definitly wrong. I think I will have to try the Jetvision DVB-T stick and see if that is better. It has been snow weather the last days, so I am thinking about static can have done some damage to the flightaware stick ?

    Leave a comment:


  • Oblivian
    replied
    Got some of my terminology wrong when referring to them saving BW and removing

    From windows feeder (which in some ways is better than the pi as you can see constant data status)

    The stream sync appears to be a realtime data down/up channel check
    You can see it remove overlapping data

    Code:
    [bs][i]Client disconnected, 2 left
    [feed][i]sent 9,0 AC
    [feed][i]sent 9,0 AC
    [feed][i]sent 9,0 AC
    [B][feed][n]syncing stream async: 1
    [feed][n]syncing stream result: 1[/B]
    [feed][i]sent 10,0 AC
    [feed][i]sent 10,0 AC
    [feed][i]sent 10,0 AC
    [feed][i]sent 10,0 AC
    [feed][i]sent 10,0 AC
    [feed][i]sent 10,0 AC
    [B][feed][i]filtering out 1 overlapping AC (saving bandwidth)[/B]
    [feed][i]sent 9,1 AC
    And unknown reasons, removing others

    Code:
    [feed][i]sent 13,0 AC
    [feed][i]sent 13,0 AC
    [B][feed][i]removed 1 of 15 AC[/B]
    [feed][i]sent 14,0 AC
    [feed][i]sent 15,0 AC
    [feed][i]sent 15,0 AC
    [feed][i]sent 15,0 AC
    And then the occasional stats update

    Code:
    [stats][e]Cached feed_id=5001 for network T
    [stats][i]sent 2684 bytes
    [feed][i]sent 13,0 AC
    And for whatever reason, occasional errors

    send - failed to send 12 + 516 bytes in mode 0, code -1: No error

    Leave a comment:


  • wiedehopf
    replied
    I'm not sure what "hits" are on flightradar24 to be honest. Maybe you have a lot of noise that is wrongly decoded as preambles but the messages are garbage.

    What kind of setup of antenna / dongle are you using?
    (If you have a lot of noise and in general to improve reception a specialized LNA is very good: https://www.rtl-sdr.com/new-product-...mhz-ads-b-lna/ )

    Are you above the trees or hills of the area?

    Leave a comment:


  • Oblivian
    replied
    And I've not seen a report to say otherwise since. But since the new uploader is capable of analysis due to keeping the 'quality' of data fr24 strive for we discovered there appears to be some unpublished/unspoken/unknown bundling of data before send.

    This likely has thresholds as to how long a contact has been lost/last heard from. And when to ignore it if not producing data within these thresholds

    So although locally you can see data, it may never be reflected after the capture and upload.

    Sent from my EML-L09 using Tapatalk

    Leave a comment:

Working...
X