I've been feeding with the following setup for quite some time, several years I think. It's always been rock solid with good results. I receive data on planes out to around 250 miles, limited I gather by their altitude and the earth's curvature. SDRPlay RSP1 FA 1090 antenna and filter up 25' on a pole LMR400 type feed line VRS MS windows dump1090 from SDRPlay's web site mlat-client.py don't know where I got this, most likely here somewhere USB cable attached to my desktop system running MS Windows 10 running VRS, dump1090, and mlat-client.py Between having to always leave my desktop machine on ( not desirable during Sacramento summers ) and all the ruckus against VRS on here lately, I've given the ADSBX feeder image a try. It took a while over a couple of days ( I'm a FBSD person, not Linux ) but it now is working. BUT!!!! . . . I have high "Sync Err #"s when I'm running on the Pi based system Same antenna/feed/SDRPlay, I just plug it into either the Win10 box or the RasPi. The Win10 box has solid #s between 0.2 and 0.5us that barely change The RasPi has #s all over the place from 0.2us up to 100us, although mostly < 20 that change each screen refresh ?? suggestions? have I made some stupid configuration mistake? has anyone successfully used a SDRPlay? Does a RasPi 3b v1.2 have enough eumph! to handle this task? Thanks! qumqats
Most likely reason is an insufficient power supply. The RPi power design is not too good and it's very picky about the power supply. If you can connect the SDRplay with a different USB cable you can try that as well. With a configuration mistake it shouldn't sync up at all.
Good "stupid simple" tip, and it did help! After 3 cables and 3 power supplies that I found around the house it's still not consistent and has lots of problems. I have a better supply on the way and will touch base with results after it's received and tried out. Thanks!
You can always test with a powered USB hub to connect the receiver. As the power goes directly to the receiver, this usually works quite well.
That's what I started out with, a charge port on a USB hub. It wasn't good Although I didn't try a different cable. I'll try a diff cable onto the hub . . .
No i'm saying you should use the hub to power only the SDR. Power the Rpi separately. Really for the RPi you want the official RPi power supply or a Canakit supply. Other supplies usually don't work well. (a MeanWell RS-25-5 also works superbly but you need some 220 V wiring experience and a multimeter to adjust the voltage) You can use the 2 command shown here to check for voltage and other throttling issues: https://github.com/wiedehopf/adsb-wiki/wiki/Debug-commands#undervoltage
The new power supply eliminates the under voltage trips I was finding in the log. But I'm still getting Sync errors often enough that my Feeder Score is usually 6 or close to. What else could be causing these? What does "Sync Err" actually mean?
Which is the feeder name and region? http://adsbx.org/sync For altitude above sea level, use either 34m or 99ft This is a good page to get your coordinates, they need to be decimal coordinates, no minutes or seconds: https://www.mapcoordinates.net/en
Is the altitude line /boot/adsb-config.txt in in feet or meters? The feeder name is either qq or qqpi depending on old ( non-pi ) vs new ( pi )
Bad sync produces bogus positions. Thus if you have bad sync, your feeder is barred from participating in MLAT until the sync is good. MLAT can be tricky .... sometimes you just need a new dongle because the one you have is dodgy. OHHHH SDRPLAY. How are you using it? Which software? I'd just get a rtl-sdr stick for ADS-B. One with builtin filter and LNA (green radarbox Flight stick, blue FA ProStick+, or external rtl-sdr LNA with rtl-sdr v3) Much less headache and you can use the SDRplay for other stuff.
ahhh I see its something new and that others are also getting hit with penalties: but I'd guess we've always been but it wasn't presented as clearly until now Yes, SDRPlay with their dump1090 on either the win10 or raspi sides. It's working perfect when on W10, and everything except mlat on raspi The preference would be to get the SDRPlay working, but I see that both the green and blue rtl-sdr sticks are under $20, so it's not really worth it! Which has the overall better receive performance? Blue stick - FlightAware Pro Stick Plus OR Green stick - AirNav RadarBox FlightStick ? Thanks!
I'd say that depends on interference. The AirNav stick is probably more resistent to interference. If you have limited interference, the FA stick is probably a bit better.
What types of things cause interference at that frequency range? I'm in the Sacramento CA area, so not major metro, but still big with lots of aero stuff going on, Mather, Sac Exec and Metro, McClellan, Northern California TRACON. The install is in a mixed use residential and industrial area.
LTE and GSM transmitters are probably the top offenders in the 700 to 900 MHz range. If you are close to an FM or TV tower that can cause issues as well. Frequency isn't so critical, high strength FM can couple into the antenna just as well. Couples into the antenna, overloads the LNA probably on the FA pro stick. The green stick has the order of SAW filter and LNA reversed. As such it's less prone to that sort of overload. If you want the best possible reception, an external LNA with plenty of filtering is used: https://www.rtl-sdr.com/new-product-rtl-sdr-blog-1090-mhz-ads-b-lna/ That's best combined with their v3 rtl-sdr receiver. Anyhow it's really hard to know which one will perform better. I'd probably go with the green stick ... with the blue stick you might end up spending an additional $15 on a filter.
I'm going for the v3 rtl-sdr receiver and their LNA/Filter. Should be here tomorrow and I'll start with the rtl-sdr reciever and FA filter I already have. Next time I'm on the roof I'll put the LNA/Filter up there and pull the FA filter off. It'll be interesting to see how reception compares with this setup instead of the SDRPlay/FA filter setup. Thanks!
update: the new v3 rtl-sdr is working like a champ and with the LNA/filter I'm picking up more and farther out. The SDRPlay is a great product, but in this use case the v3 rtl-sdr is far superior. Thanks for the help
The SDRPlay is really prone to overload from other strong signals, I use 1 for general listening and I have a chain of filters on it for it to work well. if you put that LNA/filter on it you may see improvement but just stick with the rtl-sdrv3 as it is just as good in this situation.
