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Is there a standard filter setting that accounts for the frequency error?

6 years 8 months ago #410 by briankc8
No signals was created by briankc8
Hello! Old school Radio engineer here that’s kind of new to this DUMP1090, which came pre-loaded on the Skywave Linux distro that I installed. I got it to work OK using an indoor antenna... but when I dug a little deeper into the nature of the signals using the GQRX SDR app, I noted that the frequency coming from the aircraft’s ADS transmitter is not always close to the 1090 frequency. When I took the screen shot, I had the filter set to 100 Khz bandwidth, which looks about right to capture most signals to compensate for the aircraft unit's crystal aging, component drift or just plain misalignment, which looks to be anywhere from +/- 0 to 35 Khz. That said, is there a standard filter setting that pre-sets the SDR dongle when you launch DUMP1090 that is wide enough to account for this frequency error? When I launch DUMP1090 in Skywave, it only asks for my lat/long, PPM setting, the AGC levels and if I'm using a an Airspy, RSP-Play device (Y/N)...no obvious way to set the SDR's passband filter, prior to launch.
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6 years 4 months ago #500 by meides
Replied by meides on topic No signals
Hello briankc8,

I moved your post to a new thread. The thread you originally posted it in was on a question about issues connecting to the SDR hardware. Since your post was at the far top and was off-topic, it got easily overlooked and never received an answer. Please always create a new thread for each new question.

Best,
Marco
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