New image is in order anyhow then, system is outdated.
That’s what abcd567s guides are for …
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Fully agree. Re-imaging with latest image is overdue.
I think abcd has you covered but for completeness, it’s this. Each dongle can only see about a 2.4MHz-wide slice of the RF spectrum around the frequency it’s tuned to, so you can’t cover both 978MHz and 1090MHz at the same time with one dongle.
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Althoug the 2.4 MHz-wide band is not wide enough to cover both 1090 MHz and 978 MHz simutaneously, but it allows AcarSDeco2 to simultaneously tune very close frequencies (which are within that 2.4 MHz band like following two) with one dongle.
--freq 131550000
--freq 131725000
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OK, I did the re-image, have everything in place but the UAT978 isn’t working. I ran rtl_test and received the following output, 1090 is working fine.
pi@piaware2:~ $ rtl_test
Found 2 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000978
1: Realtek, RTL2832U, SN: 00001090
Using device 0: Generic RTL2832U OEM
usb_claim_interface error -6
Failed to open rtlsdr device #0.
Is it a Raspbian image or a piaware image?
This guide is for the piaware image: How to Install and Configure Piaware 5.0 SD card image - Quickstart Guide
If you have the piaware-config correct with the serials it should work.
Do a reboot just to make sure the configuration is applied.
You can share the logs for dump1090-fa and dump978-fa via pastebin.com, see the commands to get the logs here:
Debug commands · wiedehopf/adsb-wiki Wiki · GitHub
I have ACARDECO2 running the following, --freq 131550000 --freq 131725000 --freq 131875000 --freq 131125000 which is the 4 popular frequencies in my area. The dongles I use for that is The NooElec NESDR SMARt.
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The highest frequency you use = 131.875 Mhz
The lowest frequency you use = 131.125 Mhz
The band width used = 131.875 - 131.125 = 0.750 MHz
This is well within the 2.4 MHz bandwidth of all makes of R820T+RTL2832U based dongles, hence works fine.
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This is a piaware image. I am not familiar with pastebin.com, but here is the output from piaware-config
piaware-config
allow-auto-updates yes # value set at /boot/piaware-config.txt:67
allow-manual-updates yes # value set at /boot/piaware-config.txt:71
allow-mlat yes # value set at /boot/piaware-config.txt:75
allow-modeac yes # value set at /boot/piaware-config.txt:79
feeder-id REMOVED
value set at /boot/piaware-config.txt:84
image-type piaware # value set at /usr/share/piaware-support/piaware-image-config.txt:5
manage-config yes # value set at /usr/share/piaware-support/piaware-image-config.txt:4
network-config-style buster # value set at /usr/share/piaware-support/piaware-image-config.txt:6
rtlsdr-device-index 00001090 # value set at /boot/piaware-config.txt:86
rtlsdr-gain max # value set at /boot/piaware-config.txt:60
uat-receiver-type sdr # value set at /boot/piaware-config.txt:85
uat-sdr-device driver=rtlsdr,serial=00000978 # value set at /boot/piaware-config.txt:87
wired-network no # value set at /boot/piaware-config.txt:27
wireless-network yes # value set at /boot/piaware-config.txt:33
wireless-password # value set at /boot/piaware-config.txt:49
wireless-ssid REMOVED # value set at /boot/piaware-config.txt:48
That looks reasonable.
What exactly do you mean by that?
Is dump978-fa running?
Can you show the log as requested earlier?
You paste text click create paste and it gives you a link you can share here.
Here is the output of the two DUMP files
What I mean about UAT978 isn’t working is that I am not seeing any traffic on my SkyAware site, it shows the UAT on my MY ADS-B page but the numbers are zero
So dump978-fa is running correctly if those messages are the last ones in the log 
Mar 26 14:57:01 piaware2 dump978-fa[21470]: SoapySDR: using maximum manual gain 49.6 dB
Mar 26 14:57:01 piaware2 dump978-fa[21470]: SoapySDR: using stream setting buffsize=262144
Mar 26 14:57:01 piaware2 dump978-fa[21470]: Allocating 15 zero-copy buffers
Mar 26 14:57:05 piaware2 dump978-fa[21470]: [::]:30978: accepted a connection from [::1]:40756
Mar 26 14:57:30 piaware2 dump978-fa[21470]: [::]:30978: accepted a connection from [::1]:40758
Mar 26 16:01:53 piaware2 dump978-fa[21470]: [::1]:40756: connection closed
Which SDR are you using for 978 and which antenna?
Where is the antenna located, what coax are you using to connect it?
Bingfu Dual Band 978MHz 1090MHz 5dBi antenna
AirNav RadarBox FlightStick UAT - 978 MHz USB Receiver with Integrated Filter
Antenna is located inside in a north facing window
The coax that came with the antenna
FYI - I am located 18 miles north of KORD, so a fair amount of all kinds of traffic
How is the weather, maybe not many small planes around?
You should probably reduce the gain quite a bit.
Try this:
sudo piaware-config uat-sdr-gain 36
sudo systemctl restart dump978-fa
Are you using a splitter after that antenna?
If not you could try and see if you get 1090 with it properly just to test the signal chain.
(not with the same SDR obviously)
Looking at your stats, 1090 reception seems poor as well.
But at least 1 aircraft on UAT so it is working.
Weather = KORD 262151Z 12006KT 10SM OVC022 06/02 A3008 RMK AO2 SLP191 T00560017
March in Chicagoland, so pretty much sucks
I could reduce the gain, but would like to know what it is before I change it, can you provide the command to do that ?
No Splitter
I will try the new antenna with my Orange FlightAware stick and see what happens with the 1090 feed
This receiver is facing north, so a bit less traffic than my south facing receiver
I have ordered the same UAT receiver as John Tuthill, along with the AirNav UAT 978 MHz Outdoor Antenna to add UAT support to my system. As it is “ordered” and not installed, I’m not exactly sure what to expect. From my FlightAware page, it does not look like anyone within 15 miles of me has added UAT. I am otherwise fairly new at this, so I’m not sure when degreasing the gain is needed. Is there some way to view signal to noise-floor with this? How about Automatic Gain Control, is that a good or viable option?
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There were commands included to change the gain.
If you don’t know what gain is … i suppose you can read this: Thoughts on optimizing gain
But it doesn’t completely apply to 978 … 978 you want it quite a bit quieter than 1090, different demodulation scheme.
No that’s not it the range is just atrocious.
Probably interference or just noise as in a noisy HDMI cable near by.
AGC doesn’t work for the short ADS-B messages (neither for UAT), it was built for TV signals.
With a proper antenna and an LNA in the receiver you need to decrease the gain … 36 is a good starting point.
If you get UAT flights you can check the signal range: GitHub - wiedehopf/graphs1090: Graphs for readsb / dump1090-fa / dump1090 (based on dump1090-tools by mutability)
I’d aim for a signal range from maybe -32 to -6 with UAT.
With 1090 usually something like -30 to -1 roughly speaking, the largest signals are usually squished against the -1 dB mark.
In the end it’s trial and error, checking that low flying close by aircraft don’t have intermittent tracks caused by overload, balancing that with far away aircraft which tend to quieter.
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Thanks for the info on the tool. I installed it a couple of hours ago and trying to make sense of all the graphs.
I’m seeing that the strongest signals are about -2 and the noise floor is around -24. At the moment, my 1090 tuner is at the default “max” gain. Would you suggest I then decrease the gain a bit?
When I add 978 UAT, will that automatically add its own graphs to this? I just received my tuner today but my dedicated 978 MHz antenna doesn’t arrive until Tuesday. I do have a few other antennas I could temporarily use, so I may start playing with it tomorrow or Sunday.