Can I refine my setup further?

[queen lily]

Setup as follows:
1090MHz 978MHz Dual Band ADS-B Antenna flightaware Outdoor 5dBi
KMR400 N -> SMA 15 Ft
6 inch RG316 jumper
1090 Mhz Saw Filter
RTL-SDR Blog Wideband Low Noise Amplifier Bias Tee Powered
RTL-SDR V4

Antenna on 10ft pvc pipe on eve of house. Its between a 144mhz, and 152mhz vertical antennas. Those are very intermittently transmitting.

Coax into eve, and onto a workbench with Pi & everything in line.

Getting thousands of aircraft a day.

Over a month I'm doing very well locally, but even out at 100 miles on the adsb leaderboard people have 3 times as many positions as me.

I don't receive very many ground planes, only occasionally will the local airfield grab one when i'm viewing it.

Anything on my graphs or setup that sticks out as maybe being improvable?

Running adsb.im software on my pi 4. Gain is maxed at 49.6 I'm seeing out 200 miles, and seemingly covering local stuff well.

Open to thoughts. Thanks!

[deft spear]

What's your surrounding terrain like? Maybe do this https://github.com/wiedehopf/tar1090?tab=readme-ov-file#heywhatsthatcom-range-outline to see your theoretical range, but unless you're in the bottom of a bowl, I would expect you to be able to see out to 240+ nmi.

Full gain in the SDR when using an LNA is not normal - something in the 30's would be more typical, but it doesn't appear that you have a lot of strong signals from nearby aircraft either. It kinda makes me wonder if your LNA is actually getting bias-T power?? I would expect it to not pass signals at all without power, but I'm not familiar with that LNA. A quick test might be to remove the LNA from the chain and see if that makes a difference.

[drowsy oxide]

He says he is seeing out to 200. But yes with Gail at 49.6 and an LNA i would expect messages greater then 3db to be much larger.

The Bias-T is going to be off by default, did you do something to turn it on?

[queen lily]

Yes, Bias-T is enabled in my SDR setup. when I disable it. notable drop in planes seen. On currently in pic one. Pic 2 is with it off.

I tried pulling the filter out, running just the LNA. performance tanks. Filter alone does okay but reduced range. so i'm suspecting the LNA is working.

I had swapped coax to antenna. no real difference. The skeptic in me is saying its all working fine and this is a good setup. I do have a little terrain near me so i know i'm not up and in the clear fully and my signal will be affected (similiar to my ham radio stuff)

I suppose I could fuss around with some other LNA's as this one is supposidly around 18db,so maybe i'm not really boosting the signal much. Or maybe its the antenna. I don't really have another antenna to compare to currently as rabbit ears inside arnt exactly an apples to apples comparison

[deft spear]

18 dB should be sufficient. Could be a suboptimal antenna. I'd still suggest doing the theoretical range thing. I might also try reducing gain to, say, 37.2 or so, and see what affect that has.

[queen lily]

Thanks for your thoughts. Will likely try to build an antenna and look into some additionals. might also try another 1090mhz specific LNA just for ha ha's. It feels like the setup is working well, I just always wonder if theres some other little tweak to improve things a bit more.

[deft spear]

I upgraded from a blue stick to AirSpy Mini + Uputronics filtered LNA a year or so ago, and it made a significant (though not massive) difference, but I already had everything else "dialed" as much as I could.

[drowsy oxide]

I also wonder if it’s something locational, are those feeders 100 miles away on the other side of the hill, closer to a bigger city, maybe closer to the ocean? If you are in the US could it be that the other feeders are also getting 978 traffic?

[queen lily]

I'm within 100 miles of NYC. I highly suspect that the bigger stations are covering NYC and the coast and probably have most if not all of the ground trafic around NYC which probably very amplifies their position counts and planes.