FlightAware Discussions

Tweaks


#102

That data looks like your antenna is not connected :slight_smile:

Is by chance the connector different from your other dongle?


#103

adsb2

Someone has the green adapter for (ads-b FlightStick radarbox24) radar I’m going crazy, I look at gqrx and I notice signals from adsb (I think) but with the dump1090 from linux I do not see airplanes and with the black skewer (from tdt) yes

Should we add some special parameter or something? I have tried with different gains. Thank you.


#104

Most likely the antenna is not working. can you take a photo of antenna and connection to the dongle?

What does the waterfall look like when you switch AGC off?


#105

Just for reference this is how ADS-B data looks for me in gqrx:


#106


#107


#108


#109

yeah looks like your antenna isn’t even connected.

where is that cable even going to what kind of antenna?

can you give a gqrx screenshot without the antenna connected?

please put the gain to 49 when disabling the AGC. with gain of 0 there is nothing to see.

The yellow stripe/signal you see is not really a signal it is generated in the dongle at the frequency you are tuning for.
It should not be as strong.
Could be a bad dongle.

Tune to 1095 MHz for example you will see the same yellow bar.


#110

This antenna is a ground plane 446, the other coco adsb I have it in another place.


#111

446 Mhz / 70 cm antenna will hardly pick any signal from aircrafts. Use 1090 mhz antenna.

A DIY Quick Spider or Cantenna placed besides a window will do the job.


#112

but I also do not get anything, with the other antenna and yet with the black sitck it goes well is a coconut adsb https://www.radarbox24.com/stations/EXTRPI006056


#113

Could you switch off AGC and gain to 49 please.
(Also use 24000000 in the gqrx settings as “Input Rate” and use the maximum FFT size.
My screenshot then looks like this, clearly showing ADS-B:

And make another screenshot.
Preferably with a 7 cm wire inserted directly into the dongle input.

But that yellow narrow line looks very suspicious like the dongle is not working as it should.


#114

the yellow central line continues to mark me even at other probe frequencies with sdr # and gqrx. Does that mean that it is defective?


#115

I don’t think that line is a good thing.

Is it present without any antenna connected?


#116

7cm wire, no aircraft captured with black stick 3 aircraft. …:face_with_symbols_over_mouth:


#117

That spectrum shouldn’t be so clean.

There should be much more noise visible with a wire shoved in there.

It’s toast. †


#118

They are supposed to send another product.


#119

It’s a DC offset, fairly common with these SDRs. You can try tuning a short way away from the frequency you care about (e.g. tune to 1089.5MHz)


#120

The problem is the lack of other signals or even noise.
At 49.6 dB for a dongle with an LNA it just should not look this dark blue.

You can also see that the noise floor is basically at -100 dB, that can’t be right at that gain.

But sure you can just try the checkbox for removing DC offsets i guess, that should help if it really is a DC offset?


#121

Is your FlightStick OK?

sudo apt install rtl-sdr

sudo systemctl stop dump1090-fa

rtl_test -t