I suspect a cavity filter may be the only way to filter 1100 MHz out. Might even need a bit of retuning to clip the high side a bit more. Also seems like some strong lower frequency signals too. Good luck.
The plan is to build an interdigital band pass filter and tune it using the “Noise Source” and the ADS-B.
It will be my first time building a filter
Good times! Not sure if you’ve come across this or not (I think @jerryh47 already pasted it earlier in this thread, but there is a bunch here to sift through), but it could help your design. Keep us posted on your progress.
Pro Stick Plus here with integrated filter
I guess I still need another heavy duty filter to get best performance given my graph?
Is there any go to recommendation for this kind of heavy noise
I have removed my additional FA filter on Friday.
Since then i do have a little bit improved range of approx 10-20 NM, also the reception has been increased slightly.
Looks like I do not need the filter and my spectrum result was looking pretty much the same as yours.
My antenna is line-of-sight to the interrogator at BWI 7 nmi distant. When the Interrogator is pointing towards me its 1030 MHz RF pulses desense the AirSpy SDR and/or the LNA, unless I insert the cavity filter between the antenna and the LNA. The cavity filter attenuates by ~33 dB at 1030.
So yes, I need a good filter.
I have added the Jetvision Cavity Filter, results look very good
30min frequency scans directly after each other, maybe a slight influence from dying traffic in the evening, but hopefully not
Click on the image to switch between before and after:
Do i need a filter part 2…LOL