FlightAware Discussions

Ahh a "I have been busy setting things up moment"

Don’t you hate them. Just setting up a odroid xu4 running at the moment a blue flightaware SDR, with a RTL SDR ADS-B 1090 Mhz LNA and a bias t power set up. (I haven’t used such a LNA for sometime) Now for the life of me, I forget the set up for the LNA. It has an IN and OUT +5w connectors. Set up between the Flightaware SDR and the antenna. IE: Blue SDR >> bias t>>>>> LNA >>>>> antenna.

2 questions,

which end of the LNA connects to the anteanna, the IN or OUT.

do I have to incorporate any script to have the bias t to operate. I know some SCR’s require a script to switch on the bias t


to the IN.

The OUT reads “+5V” to indicate that it want’s power injected by the bias-t on that port, so the out port needs to go to the bias-t.

External bias-t devices are just something to inject power, they get 5V and that’s all.
Can’t configure them with software.

Only when the bias-t is integrated in the dongle (rtl-sdr v3 or airspy), then you need to use software to enable that function.

Thanks, thought that is how it should go, just checking my guess :slight_smile:

I believe the FA Blue stick pro already has an LNA/amp built in and you can’t use the RTL SDR ADS-B 1090 Mhz LNA with it. I could be wrong on that as I just never got mine to work. That could be because I had it configured wrong. I’m not too sure.

I guess I should say it didn’t work well for me. IE, it would only give a range about 25nm.

I have both the Nooelec Smart Tee and the rtl-sdr v3 running on my Pis. The Nooelec’s bias T is hardware and on all the time. This makes it easy to add the LNA. The rtl-sdr v3 does need a couple of software packages added to turn on the bias T but there is a way to make it on by default at boot up with a file.

I think the LNA might be “passed on” :frowning:. When connected there is nothing, when removed, detection’s are seen. No matter, it was just lying around on the table. A ceramic uptronics LNA ordered.

Someone mentioned his board was installed backwards.

So you could just try it backwards or open it up to check.

How did you supply the bias-t?

USB power pack 5v 2.0 amp

You should also check your sma connectors if you didn’t on accident get some RP-SMA stuff.
So check if it’s pin+hole at the connection that get combined.

rtl-sdr blog support is quite good, they will send you another LNA if yours is defective.

I suffered the same type of issue. As mentioned, the LNA can be in the case backwards.

Another issue I had was two of the first bias Ts I purchased weren’t actually bias Ts but were noise filters and amps. If you have the correct bias T it will power a small LED on the LNA.

Even once I had the correct bias T and it powered the LNA it did not work well with the FA blue stick. It would drop most aircraft over 25nm and anything closer then about 10nm would drop as well.

I end up ordering both a Nooelec Smart Tee and the RTL-SRD dongle. Both of them work very well with the LNA and both out perform the FA blue dongle.