So I'm feeding right now, Pi 3, two orange FA Pro RTLs, 1090 with external band pass filter, 978 of course without Both being fed by 978 and 1090 specific 5.5dbi antennas Here is kicker though. I have a PlaneFinder dedicated box, a FR24 dedicated box and both of those have antennas too 3dbi-5.5dbi range stuff and then the personally funded ADSBX box. All the antennas are mounted to rafters just under my composition shingle roof as high as I can get them, but they ARE inside. I want to get more range especially for the ADSBX box...What is best way without moving 4 antennas to the chimney? I was thinking of this setup, pairing up the PlaneFinder and FR24 boxes and then pairing up the 978/1090 feeds for the ADSX as follows. 1) Mount 2 antennas outside, best 2 I have 2) Mount LNAs at the antennas outside, 1090 filtered for PF,FR24 and less filtered version that would pass both 978 and 1090 to the ADSX box (any suggestion for that?) 3) Get simple splitter and split signal between both sets of boxes or sets of RTLs (FR24/PF) and 978 and 1090 on the ADSX 4) Filter 1090 with same external filter Small town, open skies, not a lot of RF here. This should get me better signal more than enough extra range/gain to counter the splitting and longer coax run losses. Any advantage to moving to better SDRs like the RTL-SDR v3? https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
What type of splitter? A simple splitter will give you a -3.5 to -7 db loss. why a filter? you say "not a lot of RF here" every time you put something in line you get as a standard a 1 db loss at least. When doing calculation on cable runs even a barrel connector is a 1 db loss. why not just move all 4 antenna to chimney? That will give you best performance upgrade with what you are doing. RG 6 coax is figured at a 5 db loss per 100' what cable are you using? how many feet? add splitter loss and cable loss you may find not much improvement. Thats why I say move all 4 it will give you best improvement..
Here’s a splitter I picked up from Banggood.com. Not sure if it works yet. I need to setup a second receiver and reconfigure the pi for running both 1090 and 978. I found 978 has a lot of aircraft showing up in my area. These are aircraft I’m missing.
Any splitter will work, most important question is "how" . Y coax splitter is tested and many people confirmed it.
This is true. I was given a Stratux setup that I repurposed as a dual-band feeder for ADSBX and I could tell no difference between the Y-cable and a decent Mini Circuits splitter. Or two separate antennas for that matter. This has been repeated so often the most people accept it as truth but it is not. In many years working in RF, I have never seen that much loss in a proper coax connector or adapter at 1 GHz. Assuming there's sufficient gain in the system, what really matters is the system noise figure and a splitter won't increase that by 3.5 dB because it splits the noise as well as the signal.
Indeed. We use SMA splitters for all installs. https://www.amazon.com/gp/product/B0744CQGS5/ I buy them bulk for $4 per splitter.
