#New install, can not get MLAT feed

1 messages · Page 1 of 1 (latest)

hybrid shadow
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Hey everyone, total noobie here setting up a ADBSExchange dongle. I seem to have got the feed setup, and it shows I'm feeding ADB-S okay but nothing for MLAT. This is the bundled image.
I also tried an image I made myself, and with a RTL-SDR dongle, which also yielded the same results - no MLAT feed.
Probably something really simple that I missed, but after all my reading, it should just work with no further configuration with the ADSBExchange image.
Pi4 b running a Pi power supply as hardware.
Thanks!

Screenshot_2023-11-08_111842.png
manic swallow
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You set the location and antenna height?

hybrid shadow
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Yes I set both. Lat/Lon is correct to my location, antenna height is 124ft above sea level.

hybrid shadow
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So I changed the antenna height to 0ft (or 0m), and it now says feed okay. However I,m not seeing any being displayed, only my local aircraft I pickup on my antenna.

Screenshot_2023-11-08_150606.png Screenshot_2023-11-08_150518.png
manic swallow
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Well MLAT aircraft are not common, so seeing none at any given point in time is not unusual. Try changing it back and see if it works now.

hybrid shadow
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I changed it back to the correct altitude an it failed. I'll keep an eye out and see if it starts pulling in aircraft

manic swallow
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Weird, and your sure 124ft is correct? And you included the “ft” At the end in the format notes? @halcyon goblet this has to be height too far off correct?

halcyon goblet
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Yes, it should be, for example 124ft make sure there is no space between the last digit at "ft"

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If you put it at zero and it works, that will work. Being off by that much will not be a huge deal.

hybrid shadow
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Yep, tried both ft and m. If I use any number other then 0 if fails. Weird.

hybrid shadow
manic swallow
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Can you send a screenshot of the field and data entered when it fails?

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Feel free to obscure the coordinates.

hybrid shadow
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So I went to put in the actual height this morning to take a screen shot, which I did, and now it seems to be connected still.
So I have my antenna altitude set to 135ft and it’s staying connected. It also connects with 0, so I don’t know 🤷‍♂️

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I’m still not seeing anything but my own planes from my antenna.

manic swallow
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Also do you have a tower this is on or something? 135ft above sea level seems very high for the area in your map above.

hybrid shadow
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My house is on a hill right above a bay, which is at sea level. So yeah 125-135 is what I get with several services.
So on my feeder map I won’t see mlat from other feeders as well? There is a key for mlat displayed planes so I assumed they would also display?

manic swallow
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Only if you also see those aircraft would you get the data back

hybrid shadow
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Also right now everything is sitting inside until I get it sorted. Then I’ll mount it in my shed with the antenna in a clearer path.

manic swallow
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The hill is over 100ft tall, wow I didn't know they had hills that big in the area.

hybrid shadow
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I’m in the Skagit valley but there are some glacial carved hills. Cascade mountains and North Cascade are just a few minutes drive.

manic swallow
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Oh wow, I only passed through Seattle area quickly though and you seem a bit north of that.

hybrid shadow
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La Conner. About 80 miles north

manic swallow
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Ahh, yeah where I am at in Florida most antenna arn't more then 30' up.

hybrid shadow
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Google earth has a good representation of the area.

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So I will only see mlat planes on my feed that other feeders are also seeing?

manic swallow
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Yes, to determine a location via MLAT 4 feeders need to see the same plane, if you are part of the group of 4 or more that does the location will be sent back to you.

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If you see a plane and less then 4 others do you will see it listed on the list to the right, but there will be no symbol on the map because the location can't be calculated.