As a fellow aviator I’m quite surprised in the attitude taken.
I’ve been taught that aviators keep an open mind and are receptive to feedback in order to improve their skills and to contribute to others in improving their skills.
What I read above is certainly not in that mindset of a " just culture".
And I’m enjoying this hobby next to the flying I do almost as equally in terms of satisfaction.
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I have put this “troll” on my ignore list. My time is too short spending it with such persons.
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Afternoon all. Wanted to give an update, I have been a overseas for the last week, so have not been able to reply. I have seen plenty of interesting comments while have been away… 
As @abcd567 said above, I have only a passing interest in the Aviation part, but the rest are of interest to me… What better way to expand knowledge than by broadened and deepening that knowledge in a specific area. This communities and its contributors are a great example of what can be done, and the fact people share that knowledge freely is a great testament to their community spirit.
As for my quest… well its ran for a week… Consistent results, plan on removing the filter as that was installed before it was isolated to be a USB noise issue… I’m trying to change a component at a time, slow going but seem the week sample seems to give a good base to work from:
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Number of tracks with single message and aircraft w/o position seem to be a bit high.
Can you show us the first chat with messages? Need to check the number of messages > 3dBFS
Strange, no traces about too many messages > -3dBFS
Sorry i don’t follow?
(In the last 10 minutes, I have just removed the filter as well. I want to try and see what the profile looks like without that additional loss caused by the filter.)
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Filter back in. Didn’t help…
Could the antenna detuning be an issue due the the plates in roof?
It will have an effect. Depends on the actual tuning of the Mag Mount antenna. Did you adjusted the vertical length of the mag mount antenna to optimize for 1090 MHz?
Check out this thread for REALLY good ideas on simple and very reliable antennas. Three Easy DIY Antennas for Beginners
Hi. I bought this: 60cm 1090MHz Antenna for ADS-B | The Pi Hut
Antenna → filter → receiver → Pi
That look normal, many people have this configuration without issues.
What filter are you using and what is the part “Receiver - Pi”?
Isn’t the receiver working on the Pi or is there something in between?
Your values regarding > -3dbFS should not be higher than 5%. But this is not the case for your setup. That’s what i wanted to check
It looks like he has less than 0.5% of signals greater than 3dB below full scale. So he has very few strong signals.
I made a change at 00:00 last night:
ADAPTIVE_DYNAMIC_RANGE=
ADAPTIVE_DYNAMIC_RANGE_TARGET=40
ADAPTIVE_BURST=yes
ADAPTIVE_MIN_GAIN=20
ADAPTIVE_MAX_GAIN=60
adaptive-burst-alpha=0.3333
Here are the results: > -3dbF now at 4.4% over 24h (4.6% over 12h)
Yes, i have recognized that and it was the reason why i am asking, because it is in contradiction to the high number of tracks with single messages and aircraft w/o position.
This number should remain under 5% as a target. So this setting is fine. But i am still confused about the other values and i am out of ideas
I might try the original DiY cantenna…
just to see how that performs.
When used it’s range was better than the commercial one I have now…
Also the better range was with dump1090-mutability which in the config file had the gain set to “max” which seem to be the auto gain option…
Now I’m using dump1090-Fa is it worth swapping?
There is no hard and fast rule. It is all trial & error. Use those hardware & software which give you best result.
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Bit of an update…
I had an hour spare, so tried fitting a metal ground plate at the base of the antenna… It was BBQ tray, around 30cm x 15cm and thin… It was fitted between the filter and the base of the antenna. It didn’t go too well, ripped and looks a mess… However the result speak volumes!
Why would this make so much difference? I’m assuming its the effect of the ground plate rather than an shielding effect as I have read that this is pretty minimal.
What should I be looking for in the construction of a permanent ground plate?
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WOW!!! You may have the prize for the most improvement to any site! Remember the tin foil our parents added to the TV antenna to get a better signal?
A ground plane helps most any end fed vertical antenna, and your BBQ plate sure made a difference there. Might help to keep any RF noise from the FA receiver or Pi out of the antenna reception also. Both are likely factors in your system now.
We may start to see many of us buying Aluminum foil pans soon and adding them to our antennas! You asked about a permanent ground plate. I will be adding one to my antennas and using a cheap foil pie plate with a hole the diameter of the N connector. For you, just cut a slot from the outside and notch to make a place for your wood support. Then refold the plate to make it flat, and maybe overlap the outside a bit to maintain electrical contact. I will probably use some Duct tape to hold it together. It does not have to be perfect at all. No idea if larger plate is better than smaller though minimum size would be the quarter wavelength of 69 mm.
I will be doing this test soon, but may get push back from SWMBO (She Who Must Be Obeyed) due to the test system is in my office area. Adding this to the main system attic antenna will be a bit more complex than your installation. Should be interesting, assuming I do not fall through the ceiling.
Looking at your Signal Level graph, you might be able to increase your gain by one step or more. Depends on what you already have it set at. A cooling fan over that heat sink should also help keep your Pi at lower temps in the attic. Have the fan blowing into the Pi area as that seems to keep things cooler inside.
And as a second experiment, lower the antenna and other hardware until the top of the antenna is a couple of inches below the metal stud reinforcement plate. Just to see if that helps the antenna perform better than it already does with the amazing ground plane you created. It might improve reception.
Anyway, congrats on teaching all of us about this tweak! Your graphs and photo could be a good topic to start a conversation about ground planes on all our antennas.
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Yes, they do!!! Amazing improvement. 
Congratulations. Happy experimenting.