An earlier thread has closed, so apologies if this is covered elsewhere.
I disabled adaptive dynamic range in piaware-config.txt a couple of weeks ago. My sudo cat /boot/piaware-config.txt says adaptive dynamic range is still no today 11Aug2023 @15:30.
Signal range and noise change when adr is set either to on (lower noise, shorter signal range) or off (higher noise, greater signal range).
Noise:
Signal Level:
I changed the adaptive dynamic range setting to “no” around week 31, messing around with different gain settings. However, the graphs1080 doesn’t show my last reset to “no” which should have resulted in more range and higher noise but it doesn’t. Rebooted, restarted, powered off and on (to add a fan).
Did you set a value for the gain ? If so what is that value ?
Check with command pi@piaware:~$ sudo systemctl status dump1090-fa -l
Last line of output of above command piaware dump1090-fa[1254]: rtlsdr: tuner gain set to XX.X dB (XX.X being the value)
If you have fixed gain then you should also see
dump1090-fa --quiet --device-type rtlsdr --gain 42.1 --fix (gain 42.1 is my gain so you could see a different number there and with fix being the indication that you do indeed have a fixed gain).
If you don’t see that set a gain value:
Set gain to value 30 by giving following command: ( 30 is used as an example, modify to your own liking)
pi@piaware:~$ sudo piaware-config rtlsdr-gain 30
#The above command will output following: Set rtlsdr-gain to 30 in /boot/piaware-config.txt:60
Restart dump1090-fa to implement the newly set gain value pi@piaware:~$ sudo systemctl restart dump1090-fa
Verify that the new value of gain is actually implemented pi@piaware:~$ sudo systemctl status dump1090-fa -l
login as: pi
pi@piaware:~ $ sudo systemctl status dump1090-fa
● dump1090-fa.service - dump1090 ADS-B receiver (FlightAware customization)
Loaded: loaded (/lib/systemd/system/dump1090-fa.service; enabled; vendor pres
Active: active (running) since Fri 2023-08-11 19:46:42 UTC; 1h 14min ago
Docs: PiAware - ADS-B and MLAT Receiver - FlightAware
Main PID: 520 (dump1090-fa)
Tasks: 3 (limit: 4915)
CGroup: /system.slice/dump1090-fa.service
└─520 /usr/bin/dump1090-fa --quiet --device-type rtlsdr --device-inde
Aug 11 19:46:42 piaware systemd[1]: Started dump1090 ADS-B receiver (FlightAware
Aug 11 19:46:42 piaware dump1090-fa[520]: Fri Aug 11 19:46:42 2023 UTC dump1090
Aug 11 19:46:42 piaware dump1090-fa[520]: rtlsdr: using device #0: Generic RTL28
Aug 11 19:46:42 piaware dump1090-fa[520]: Detached kernel driver
Aug 11 19:46:43 piaware dump1090-fa[520]: Found Rafael Micro R820T tuner
Aug 11 19:46:43 piaware dump1090-fa[520]: rtlsdr: tuner gain set to 38.6 dB (gai
lines 1-15/15 (END)
Not a pro user but I don’t see any problems. All my data are good.
Go by what your dump1090-fa is telling you and what piaware-config is telling you.
I don’t think you can intuit that from the graphs. You want a gain which gives a signal range that covers the range of your receiver as much as possible. If you have that then you’re about right for maximum reception, regardless of whether ADR is involved and what the graphs appear to show.
There’s a clear difference between ADR being on and off. My .txt piaware-config say off, graphs say on. It’s not even close. I don’t have a lot of noise (based on earlier noise data) but not good radio horizon either. Trees up to 98 feet (29.9 metres).
You and I are fairly close together location-wise, have a reasonably similar setup including a good antenna that’s mounted about the same height (~25 ft ?). I’ve parked my gain at 43.9 which seems to be working well. I had the adaptive gain on and never saw it change but only a few times and then only for a few hours, if that. I think altitude may be the last variable to get better numbers and even then could be a diminishing return based on the number of aircraft to the east/southeast that we can see.
Hi @vannossc! I like to joke that this is my Etihad stamp-collecting hobby lol!
Gain at 39-40 seemed to work from my trials. The difference in signal level (i.e.-20 dbfs adr on and -8 dbfs adr off) seems worth it given the not-so-bad noise. Right now I’ve set it back to ADR off and rtlsdr gain at max. I’ll see what happens. Surprisingly, noise isn’t too bad here.
Anyway, taller (i.e. antenna height) is always better!
That looks lovely, very relaxing view! And a nice view to the horizon. Maybe it would be worth you getting a preamp and then adjusting the gain down to maximise the range of quietest to loudest signals. Myself and friend have the Uputronics filtered SAW preamp and get excellent range and results, me indoors and friend on his roof. We both have the FA antenna which is also excellent.
I’ve used this approach on both our sites, it works brilliantly and gets the gain to the best place within minutes rather than days of testing or graphs analysis. In SkyAware you can enable the RSSI column and sort by it (click the column name) and see weakest to strongest signals. You can then adjust the gain manually in piaware-config.txt and then do a sudo systemctl restart dump1090-fa.service to see the changes immediately with almost all the same aircraft in view as a reference.
A high gain lifts up all the weakest signals and makes the stronger ones all too strong, some to the point of being illegible. A low gain lowers the stronger signals but if it’s too low they become needlessly weak. It’s akin to the stick being a fixed window, and the range of signals strengths received being a sliding block, and the gain’s job is to allow it to expand as much as it can while still fitting inside that window.
It’s also very susceptible to strong RF close by. If you’re a radio ham and have 2m/70cms aerials then even a couple of watts on either band will totally flatten the uputronics LNA. Just something to be aware of.
