FlightAware Discussions

Twerking my system

Hi just introduced a splitter with into my system and getting better results on both r2 and mini sharing FA antenna
can you spot a different way or maybe a tweerk or too
fa antenna - 5m - rtl lna - 5m - bias tee separate psu - splitter - r2 - pi4 2100mhz

GAIN= 21
OPTIONS= -v -f 1 -p -x -e 10.5 -w3 -t 200

splitter - airspy mini - pi4 2100mhz

GAIN= 21
OPTIONS= -v -f 1 -p -x -e 10.9 -w 3 -t 120

4 x short sma m - smm leads arrived today
i bought 2 splitters very nice
no lost samples


If introducing a splitter improved the performance of both receivers, that would suggest to me that your gain may be set a bit high. I used to run it at 17 on my mini, and reduced it to 14 and saw an increase in reported positions. I didn’t lose any range or message rate by making the change. I’m also using the rtl-sdr lna.

My signal strength graph looks like this:

The airspy is more tolerant of strong signals than the rtl dongles are, but it still benefits from having the gain set appropriately.

Thankyou for reply
i will try altering gain now i have both connected
i have this coming to very soon

I bought six 1090Mhz, six 978Mhz and two 144.39Mhz versions of that Cavity filter. They work well for me.

Great to know they are good
cant wait to get it slow boat grrr

1 Like

Interesting. I did the same two days ago. But I added a second LNA to my setup to cover for the loss the splitter introduces. My signal chain looks like this:
FA-antenna -1m LMR400 - RTL-SDR LNA - 10m CLF200 - bias-t injector - Uputronics LNA - splitter - R2/mini - PC (R2)/RPi4 (mini).

I also got better results. Most noticeable improvement for me is better coverage in the direction of a large tree I have 10-15 meters from my antenna. And also slightly better message rate over all.
Since I’m terrain limited, the range has not been improved.

I lowered the gain from 18 to 16, trying to keep my signal strength about the same as before the splitter and the added LNA.

My main goal is to see if the PC gives better performance compared to the RPi4 due to the fact that I can use higher -e-values on the PC compared to the RPi4.
I’m aiming at running the two systems at roughly the same load (85-90% CPU for airspy_adsb) and see what differences there are.

Why nobody addresses the elephant in the room?

Twerking my system