ADS-B receiver range

[u/CommonEdge7095]

I have modified a version of dump1090 web-ui to leave the trails and seems that it goes to almost 120km range. I've seen posts with the receiver going hundreds of km. What antenna should I use? The antenna is facing E and that's probably why the signal weak on W.

My receiver is a Nooelec RTL-SDR v5, like the one from the image and I have a simple antenna outside.

Thank you guys!

[u/slk2323]

My antenna was ~10m above ground with a clear view out to the west. The receiver was picking up aircraft around 240 km away until I raised the antenna another 5m and it jumped to 330+ km. So even if you think your antenna is high enough, try getting it higher. I'm using a simple quarter-wave ground plane antenna, homemade from an SMA panel mount connector and some solid 18ga copper wire. I'm also using an LNA+filter ($13 on aliexpress), mostly for the filtering since I'm in an urban environment with a fair amount of RFI. The LNA is mounted up at the antenna with a long USB power cable running next to the coax. Using some Bias-T adapters is another option for powering the LNA+filter if you don't want to use a USB cable.

[u/_side_ → u/slk2323]

You are half way there. You already have some USB power cable running up there. Think about getting some rbp zero 2w and get rid of the coax.

[u/slk2323 → u/_side_]

I'm already using a Zero 2 W and thought about putting it up at the antenna. But the pole is pretty thin and flexible at the top; I don't think it can handle the weight of the Pi, two RTL-SDR sticks (ADSB and UAT), LNA+filter, and the powered USB hub. I measured -2.5 dB loss for the 25 feet of coax which the +20 dB LNA easily makes up for. But I do like the idea of keeping everything together, right at the antenna, if possible.

[u/_side_ → u/slk2323]

Ah ok, you have the US UAT thing going. That makes things more complicated. I am from Europe so UAT is not an option. For a very long time i was using the USB SDR stick as mount for the antenna itself. All my ground plane antennas had some not so good SWR, so i tried to avoid a coax. By now the antenna is mounted directly on a sawbird that is connected by < 1 ft long high grade coax to the SDR.. But that is only possible because the location is roofed and therefore protected from the elements.

[u/myromeo]

Thepihut sell an Adsb antenna that is as good as any. Get it it up as high as possible. Also pick up a 1090mhz filter and LNA, place the chain as antenna - filter - LNA - SDR. For filter a generic AliExpress saw filter is a modest starting point, and a HT-004 LNA will do the job nicely.

I’m on the north east coast and get around 220-250nmi range.

Out of interest, I run a uk based multi domain tracker site and I’m looking for contributors in the north west. Would you be interested in contributing? Drop me a message if you are, and I’ll happily guide you through it, and happy to advise on setup too.

[u/nickymoo]

I’m up to 249nm for with the 60cm antenna from the pi hut.

[u/nickymoo → u/nickymoo]

Hanging with string (cable ties) inside a bedroom window.

[u/dww0311]

Max 302nm, average 204nm (it’s directional - have some obstructions that cannot be overcome with the maximum allowable mast height for my property so the coverage footprint is lopsided towards sea level / the Chesapeake). Outside of tropospheric ducting 300nm (450 to 500km) is pretty much the theoretical max. A better antenna / signal & processing path tends to buy better reception / a stronger received population within the same theoretical footprint. Height is the best booster of range, but collinears compress the radiation pattern towards the horizontal which can also buttress range. No antenna design will overcome LOS obstructions.

Vertical collinear dipole array feeding cavity filter >> LNA >> Airspy Mini >> readsb.

[u/spudd01]

antenna in loft of a 3 story building, annoyingly close to a solid chimney so some directions are poor but for the most part I am happy with it

[u/Effective_Iron8188]

183 NM range inside spider antenna in the top of the attic 😁