FlightAware Discussions

Newbie to adsb

Hi guys,

This adsb is a totally different ball game to me .
I have an ebay bought a small homebrew plastic antenna around 20cm long on the roof and 10m of Messi and Paoloni lowloss coax with connectors too. I am using the flightaware usb stick pro plus (lightblue one) from pihut and a rpi4b 8gb.

I don’t think I’m receiving as well as I should be here on the west coast of Scotland UK.
I am around 27 miles west of Glasgow int Airport in Greenock.
I seem to be pulling in the 50-100 mile range flights but not the further afield flights.
Could there be a problem with gain and is there a command to adjust the gain on the Fa stick?

Any help appreciated TIA

Regards

Rab

I’m fairly new to ADS-B receiving as well. FWIU, Piaware sets the pro stick into AGC mode by default. So, you’re probably running at maximum gain now. There are a couple of threads on the forums here about the method of setting gain manually.

Antenna height and gain are going to make the most difference. If you are located in a heavily wooded area and/or surrounded by hills you will have to take that into consideration as well.

It might help if you can include a link to the antenna you purchased off eBay. Thanks!

Get graphs1090 to be able to better judge changes to your setup:
GitHub - wiedehopf/graphs1090: Graphs for dump1090 (based on dump1090-tools by mutability)

If you want a range outline, here is a guide for tar1090 (requires tar1090):
GitHub - wiedehopf/tar1090: Provides an improved webinterface for use with ADS-B decoders readsb / dump1090-fa

The range outline is a calculated range based on your location and the hills around you.
Optimizing gain · wiedehopf/adsb-wiki Wiki · GitHub

Gain is unlikely to be the reason for your limited range.
Either it’s hills / other obstacles and you can’t change it.
Or it’s interference and you need a filter.
Well there’s a third option, a coax that attenuates the signal too much.

If you let people know your gain setting and show your signal graph from graphs1090 … some educated guesses as to the issue can be attempted.
That is after adjusting the gain as described in the link (having run the rough adjust for this: Automatic gain optimization for readsb and dump1090 fa · wiedehopf/adsb-scripts Wiki · GitHub)

-10 or AGC is the hardware AGC and it will result in max gain due to ADS-B messages being too short for the AGC to correct the gain.
Thus it’s only useful if you want max gain.

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Hello @wiedehopf,

Thanks for taking time to point me to this information.
I swapped my tiny 20cm antenna over onto a marine AIS antenna which is 1.5m in length.The coax I am using is Messi Paoloni ultraflex 7 with pl259. I understand I should be using N type connections.
The results were a big difference at 165nm + as opposed to the 50-100nm
There are a lot of hills around me but I am located quite high up among them.

Do I install the github links through terminal/ssh and if needed is it possible to use the filter with the fa pro stick + given there’s already a filter/amp internally already?

I will post more info when I’ve carried out the tests

The fa pro+ has the LNA before the filter, such overloading of the LNA is possible.

If the AIS antenna works better than the other antenna, could be that the other antenna is very very terrible or that the interference isn’t picked up by the AIS antenna and thus you get better reception.
Either way if you want the best possible reception you’ll need an ADS-B antenna.

FA makes one, vinnant.sk offers a good one, there are other choices.
The connector is secondary to using an antenna made for the frequency.

Well how else would someone install something on the pi? :slight_smile:

Hi wiedehopf,

sorry for my newbieness I installed the scripts and had a look through them.
I also contacted the guys at jetvision.de to see about the radarcape 66066 do you think this will do any better?
I’ve also been onto Vinnant antennas and have enquired about the 5/8 wave colinear 7.5.

Hopefully see some improvements with a bit of tinkering and a few upgrades.

This graph is from yesterday with small adsb antenna

These graphs are today using a sirio 2016 20ft antenna (temporarily)


For the record I do not really know if these graph readings are good or bad.

Again thanks for your input and advice

I am owning a Radarcape device (AirSquitter) and can say it performs a little better than a regular stick, but not as signisifcant as you might expect it. Depending on your environment it cannot do any miracles. At least not for the price they call out.

Using an Airspy in combination with a filtered LNA is delivering the same results as a Radarcape device (depending on your individual setup and location)

I would rather find the root cause for your limited performance.
Did you check also heywhatsthat.com regarding your max. range based on location?
This is sometimes also the limiting factor.

A good starting point is also other receivers around you and their performance, even if this not automatically an indicator

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Get the FA filter to test if that makes a difference.
Easy test before you even consider something that’s really expensive.

If you want to hear about other premium options, this might be a thread to look at:
Building a new receiver, this is going in a prime location - Suggestions for receiver/preamp/filter please

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OK @foxhunter @wiedehopf,

I think that is my problem. I buy too much unnecessary equipment rather than troubleshooting I think the answer is buying more expensive gear… But end up with the same problem and out of pocket.
Exactly the same with ham radio however I find the adsb/ais more interesting.

Thanks guys. I will try the filter first as I have a feeling it maybe overload.
The feeders directly around me don’t seem to be doing much better than me with the exception of one or two who seem to be at a higher altitude away from hills.

Really appreciate your help.

Thank you

Then you should not expect too much from your setup, independent of the used devices

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I have a feed into my VRS from a receiver in Roybridge which is a fair bit further north than you and this is his heatmap over the last few weeks.

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Hi @keithma, cheers for the input and replying to me.
Is there a link where I can see the heat map you are displaying or is this your own system?

I’m located in Greenock, Inverclyde and quite high up, however there are lots of hills around me…
For testing I’ve linked a marine antenna and sirio 2016 large metallic antenna together and seem to be pulling in a lot further.

I spoke to the lad at vinnant antennas and I’m waiting to order a colinear antenna (with groundplanes) at 50 something euro.

My aim is to link this to a filter and if I see improvements upgrade to a radarcape 66606 and take it from there…

Best Regards

For such a heatmap you will need to install Virtual Radar Server.

But you can also feed to Planefinder. They’ve upgraded their system and you can get such a heatmap there as well. The advantage is that you do not need anything else beside the feed to Planefinder.
https://planefinder.net/coverage/client

A second option would be the installation of ModesMixer2. This is a locally installed application with a web interface giving you such range plot as well (but without an underlying map)

user @abcd567 has created an install script doing the job:

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How did you hide all aircraft in VRS to show only the heatmap?

Answering my own question. I just switched to my UAT receiver which I configured in VRS, but doesn’t add any aircraft positions. :yum:

Yup, that’ll do it. What I did was to just select a different receiver.

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