That’s strange, would have expected less of the all frequency noise.
Might just be the cable is loose or something like that.
You can also check for under-voltage on the rpi:
dmesg --ctime | grep voltage
Low voltage can cause bad dongle performance.
(for example a USB cable between RPi and dongle)
What is the antenna/cable you are using?
This is just my easy access test area, mainly for software.
It is under a thatched roof (about 1m of damp straw, so not good for any sort of range).
I have access to a much better setup, but this requires good weather.
I will have to bite the bullet and lower the mast.
Sorry, antenna is a flight aware 5dB? IIRC
Oh i didn’t look up what a thatched roof is, sorry 
And that’s gonna be indeed suboptimal.
So the broadband noise you see can of course be also be generated by the front-end being overloaded by interference.
So you might just need a filter.
If you have the rtl-sdr v3 stick already, i would just get the filtered LNA because standalone filters aren’t much cheaper. (New Product: RTL-SDR Blog 1090 MHz ADS-B LNA)
This will especially help under that roof because it can better pick out weak signals.
For really good reception you’ll still need to put the antenna on the mast but it’s a start.
Wideband LNA on mast with 10m LMR600 cable to rtl-sdr v3 stick.
Loads more signal, most of which isn’t wanted!
Is it receiving anything?
Might need to reduce gain to 25 or something.
219 aircraft, 165 with messages.
That’s not bad at all
Combined with the cavity filter on the way it should work even better!
If the wideband LNA isn’t overloading.
wiedehopf “That’s not bad at all”
Combined with the cavity filter on the way it should work even better!
If the wideband LNA isn’t overloading.
[/quote]
With cavity filter between antenna and LNA.
Not as good as I hoped for.
Looks like a comb of spurious products, I’ll turn the gain down from 30 to 10dB
Curious.
I wonder if the combs are from the LNA or the dongle.
Should be from the LNA, the dongle shouldn’t do this especially not with a gain of 10.
Maybe it’s a lower frequency with so much power that the cavity filter doesn’t attenuate it enough.
You could do an extended scan 100 MHz to 800 MHz.
If the combs wouldn’t continue through 1090 MHz they wouldn’t interfere with reception.
Might still be weak enough to not make a dent in reception.
How is your reception anyway?
https://flightaware.com/adsb/stats/user/rachelclairefarrar
You haven’t claimed your receiver yet?
Ah i see. Seems to be quite some gain on that amplifier.
Try running a gain of 30, maybe 35 in dump1090-fa
Or are you running something else?
Have i done anything wrong?
Setup: RTL-SDR dongle V3, RTL LNA filter, gain set at 29.7
I’m having about 1000msg/sec,with 113aircraft and 97 with positions
Please check my results:
Is this because of the triple LNA filter?
Dont know.
Got mine only last evening.
Have yet to solder power supply wires to Bias-T (soldering iron burnt-out)
Got mine activated with bias tee via rtl sdr dongle. Raspberry Pi → dongle → LNA filter → 15meter coax low loss → Jetvision A3 antenna 1090mhz
My receiver is close to a wifi mesh system could this give any problems?
It could but it shouldn’t.
What is the output of this:
awk "$(cat /run/dump1090*/stats.json| grep total | sed 's/.*accepted":\[\([0-9]*\).*strong_signals":\([0-9]*\).*/BEGIN {printf "\\nPercentage of strong messages: %.3f \\n" , \2 * 100 \/ \1}/')"
The scan is very very strange.
To be honest i wonder how you are getting even those results with that scan.
You don’t by chance have another dongle plugged in where that scan could come from, it’s really puzzling.