FlightAware Discussions

About the coverage

Hello everybody,

I´m new in feeding flightdata. Today updated the PiAware to newest version(3.8.1)
I have dongle like THIS
Antenna like THIS
My location is Finland and with that setup i can get about 50-60NM coverage.
I suspect that it is quite bad result. Can anyone please give me some pointers what I´m doing wrong? Antenna position/location does not matter at all, coverage remains the same regardless where i put the d**n thing.
Thank You in advance.

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Maybe chosen the wrong time to start, air traffic is extremely low due to the travel restrictions.

Where is the antenna located? Higher and outside are the importand factors here.

What type of cable are you using?

Are you in the city or in the countryside? Cell phone towers can overload your receiver so it might be necessary to add a filter.

At http://heywhatsthat.com/ you can find out what the maximum your antenna can “see” because of terrain.

Apart from that, the rtl-sdr-blog dongle is quite good, you could add their adsb-filter/amp and power that via bias-t.

No idea how good or bad that antenna is…

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Another item to consider is what is your gain is set at. (-10?)
As many have experienced with good quality set-ups/better antennas, is that nearby cell towers can effectively overload the ADS-B receiver. You may need to look at various threads on the forum regarding “gain settings” and “do I need a filter” to explore if that is a factor with your system & location.

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Thank you very much for quick response.
That is correct that traffic is quite low. But something is still flying straight over :smiley:
Sometthing that i noticed is that planes that are flyng around 5Km high are seen up to 50 NM. But planed that fly over 10 Km high are seen about 60NM.
I changed the antenna location from the worst(inside next to window) to best possible(outside,over the fooftop, no buildings some trees). It does not to seem to make the difference in signal strenght.
Cable came with the antenna(was advertised as high-quality :stuck_out_tongue: )
I locate in city so cell-phone towers are present.
heywhatsthat.com does not cover my region :frowning:

To give you an idea about how the situation impacts the range:

My normal range (average max) is +150 NM on a regular busy day (before Covid-19)
Currently i am happy reaching 115NM

Any obstacles in your way? Mobile network towers, high voltage powerlines close? Trees? Hills?
Which gain setting are you using? Which hardware? Generic DVB-T dongle without filter/amplifier?

How does it come that Heywhatsthat is not covering your region? Did you create a new profile?

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He mentioned that he was in Finland - doesn’t HWT have a latitude limitation?

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Thank you for reply.

Yes the gain was set to -10
Will keep searching the forums to find out the right value
Thank you

Thank you for the reply.
Few trees are the only obstacles that I have. No cell towers,hills,powerlines etc. in visual range
About those trees, there is not much I can do.
Gain is -10 default. Raspberry with the dongle(link to dongle and antenna are on my first post) no filters of amplifiers.
It seems that heywhatsthat does not cover scandinavia.

Simply reduce step by step and leave every value running for at least a day. However with the current low traffic it’s hard to find the right value.

Possible gain settings below. the higher the number, the stronger the gain.
don’t be too confused as “-10” is somewhat special. Some here in Forum says it’s something around 55.

I would start at 49.6 and go backwards.

0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6

It could also be that you need an additional filter.
`

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Thank you very much for great tip.
Will continue as guided.

There is no universal “right value”. As above, have a play and see what works for your site / hardware setup.
Also, to some extent, it depends on your interest:
If you want to ID the plane that flew over your house, having a high gain setting may cause close aircraft to overload your receiver.
If your interest is max range, then you may need to sacrifice some close signals.

The RTL-SDR V3 is a very good general purpose receiver. To optimize it it for ADS-B, they offer a matching filter/amp that will significantly improve your performance.

@biekerc asked about the cable you are using. Did you buy or make the cable? Could you post a pic of the SMA connector? (unplugged)

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Yes, it has a limit of 60 degrees north (but Alaska is covered, probably due to the fact that the data comes from NASA). Almost all of Finland is located north of that limit.

@EELaur, I live in Sweden (2 hours north of Stockholm), you should (when things get back to normal) see a fairly decent amount of traffic between Asia/Middle East and the EU. once you get you coverage sorted.
I would check the connections, cable and probably build a simple spider antenna (to check that your antenna is working properly).
You can get some nice tips on simple spider antenna here

Good luck!

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Thanks, i wasn’t aware of that.

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Can you better describe your gear?
Antenna model, coax used, SDR used.

Have you tried mounting the antenna on top of the roof so it’s clear of the rest of the building?

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Both in his initial post:

I´m new in feeding flightdata. Today updated the PiAware to newest version(3.8.1)
I have dongle like THIS
Antenna like THIS

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Hi @EELaur,
I don’t go to AliExpress so don’t know which radio you are using, but if it doesn’t have a built-in notch filter like the FlightAware Pro Stick Plus, you will possibly have more issues with interference and swamping of less powerful signals. Just reducing gain may help some but you will also be reducing ADSB signal strength at the same time. A notch filter blots out interference depending on how far away it is in frequency and lets your amplifier gain just amplify the signals of interest. If your radio doesn’t have a notch filter already, and you do have near cell towers, that might be a place to look. Separate in line notch filters for ADSB signals are available.

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The links go to RTL-SDR Blog V3 USB Stick and an antenna which looks like a Flightradar antenna for 1090 MHz

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A “notch filter” (or band stop filter) is also useful, but the opposite of the band pass that we normally use.
eg. you could “notch” a local transmitter, but not the signal you are interested in.

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Thank you all for the answers. This is getting too complicated for me.
I´m not good at all with radio/electronics.
I got the wrong impression of this all thing. I don´t want to build the antenna tower, cut down the neighbours trees, manipulate powerlines or blow up cell towers.
It seems that all those things are present at my location.
My understanding was that it is “simple” plug and play setup when you have the right components.
All of those components that I have are suggested to be good. It seems that it would be much easier to let it go at present moment or otherwise I will find myself in a room full of equipment. I´m very sorry if my tone seems to be arrogant but it´s quite frustrating to have this s***t result. It feels like driving a ferrari at 1-st gear

But now when I have let it all out let´s get back to the issue.

@wiedehopf It seems that antenna is not relevant component at all. I have moved antenna inside, outside, on the roof, on the ground and at the moment it is in the middle of the garden on top of 2M pole. Also i tried the dipole antenna that came with the SDR. no matter what was the antennas lenght or position the results are always same 50-60NM

@biekerc The cable i use is bought, not made by me. Will attach picture of SMA end.

You’re right. I should have just said filter. Had notch on the brain.

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