Feeder hardware in urban area

Hi,
I'm thinking about setting up a feeder. I do already have a rPI. For the ADSB receiver, it looks like the FlightAware Pro Stick Plus is the way to go but I wonder what signal I would get given that I live in central Berlin (Germany). My flat is on a 3rd floor of a 5 floor building and I do have a balcony.

Thanks for your tips

cheers

 

Ads-b radio signals propagation work pretty much on a line-of-sight model, so what you will get depends very much on how much open sky you can view from your balcony,
even if there is lot of traffic above your head.
Pro Stick Plus is the right choice, the integrated filter will help you to get rid of noise and strong cellphone tower interferences.

 

ok thanks!

 

I agree. Good advice.

 

I had the curious situation of living in a ground floor apartment in Manhattan with about 3% of the sky visible. So some of the busiest airspace anywhere with pretty much the worst possible RF conditions. It kinda averaged out to a decent but certainly not particularly great or terrible setup. Range was limited to 30nmi but within those 30 mi I did pick up almost all aircraft going in or out of LGA but only one way in or out of EWR and JFK. A low-noise amplifier in the RX chain did help but not as much as you might think, problem was definitely not the strength of any signals it was all the RF and multipath interference and if I turned up the amplification too much it just killed everything by overloading the RTL. Actually I'm pretty sure most of the signals I was receiving were being reflected off the buildings across the street because MLAT worked noticeably better when I set my position to across the street and increased the elevation setting by about 20m, which is where my phone told me I was when I used GPS-only positioning, it's a lot like trying to use GPS indoors, it still works just not very well, makes sense since they're on similar frequencies.

So lets just say you should have a much easier time than I did if you actually can see any sky. 5 miles from the empire state building where most TV and radio transmitters for the city are located. the FM radio signals were so strong and the quantization error of an RTL-SDR so poor I could listen to the aliases of any very strong FM stations at 2nd, 3rd, and 4th harmonics of their center frequency.. So yeah basically the SNR was guaranteed to be shitty no matter what and by far the most important thing is a good 1090 MHz notch filter, even better if it's builtin to the receiver with an amplifier.

From what I've seen having them as three separate devices, unless you're running a very long feeder line it doesn't really matter if the filter and amplifier are on the receiver or antenna end of the line, and replacing the three with a $10 RadarBox FlightStick made everything work much better than anything I was able to get out of any different configuration of a separate filter and LNA or antenna or feedline. I was just using a simple vertically oriented dipole antenna, that worked a lot better than anything I was able to get out of whip ground planes, makes sense if the signals really are coming from across the street rather than straight up in the sky; the straight up null in a vertically oriented dipole doesn't much matter if you're not receiving any EMF from straight up anyway; but the latter might work better with more straight-up sky view like from your balcony, but it also depends on air traffic patterns; if nobody's flying overhead a ground plane might not help you with a perfect sky view. The aircraft themselves do after all use vertically oriented dipoles to transmit the signals, since ATC isn't generally located directly underneath the aircraft.

 

A little informal test and I am no expert. The 1090Mhz antenna feed is the same, during the same period of time, for both the RTL-SDR dongle and Flightaware's Pro Stick Plus - split off of the main feed from the antenna. As you can see the Flightaware dongle does very well in comparison. For giggles, I purchased a Flightaware filter (the one with the light blue label going around the cylinder) and put it on the feed going to the RTL-SDR dongle and it only improved slightly. The two aircraft seen along the east coast, beyond international waters, are non-existent on the RTL-SDR. The increase in distance is prevalent in all directions. 11 aircraft vs. 42.. .hmmm... I know what my choice would be.

So, if you are just tracking the planes, get a Flightaware Pro Stick Pluse - the dark blue plastic casing, not the orange one.

 

FA Prostick has amp and filter.

RTL-SDR is just a good general all purpose SDR. You'll need to AMP this as well to do a good comparison but FA blue probably still wins.

 

Agreed. But, I was still amazed at out of the box performance. I ordered another one.. LOL

 

@wiedehopf Daddy likes. Thanks for sharing. I'm going to order one and check it out.