FlightAware Discussions

Is this going to be a problem?

That setting is only for the piaware sd-card image. Are you using that?

This is true only if you are using Piaware SD card image.

There are 4 distinct cases, each slightly different:

  • Piaware SD card image
    For all settings, use sudo piaware-config [parameter] [value]

  • Raspbian image with dump1090-fa and piaware package install
    For dump1090-fa settings, edit file /etc/default/dump1090-fa. For other parameters use sudo piaware-config [parameter] [value]

  • Raspbian image with dump1090-mutability ver 1.15~dev and piaware package install.
    For dump1090-mutability edit file /etc/default/dump1090-mutability. For other parameters use sudo piaware-config [parameter] [value]

  • Pi24 image with integral dump1090-mutability ver 1.14 and piaware package install
    For all paramerter edit file /etc/fr24feed.ini. Gain settings are part of following string:
    procargs="--net --gain xx -- lat xx.xxx --lon yy.yyyy"

    For Beginners: How to Change / Set Gain


Thanks to everyone who helped with this. Dump1090-FA with FA and FR feeders are running on one of my antennas with one dongle on one Pi so I’ve got a spare to play with again.

I’ll let you guys know how I get on with my new kit when it arrives.

In the mean time, I’ve reinstalled dump1090-fa and graph1090 on my spare Pi and installed flightairmap.

Then I configured modesmixer2 on the PC that hosts Virtual Radar so that it collects data from both Pi outputs and VR so that it takes the aggregated data from modesmixer2.

At least I can see everything I’m receiving even if I can’t upload it all.

VRS can handle multiple inputs, no need for the extra software.

I had VRS set up with data from both receivers from the start but could only view and log one at a time. Do you configure them as merges so that you can see aggregated data or what?

Yes that is exactly what you do. I hadn’t really looked at that function before.

I’m actually rather annoyed with myself now because I’ve had both dongles running on different PCs in different parts of the house with VRS collecting data from both since day one and because I hadn’t looked at merged feeds, I wasn’t logging one or the other of them. That’s four years worth of extra data I’ve missed.
@glennblum was right. I will learn a lot here!

Resurrecting my thread.

I have been running the RTL-SDR V3s on my RPis for a while now using my existing antennae and cabling and have seen a definite improvement in all respects.

Apart from moving one of the antennae a little off the centre line, that was all I changed. There is obviously still room for improvement but it is hard to know whether the problem is the antennae, the cable or the terrain.

The next step is to install the LNAs in the loft.

I’m currently using RG6 type cable with runs of about 8 metres and I got some male SMA to female F-Type pigtails when I ordered the kit as I was planning on continuing to use my existing cables. But now I’m wondering if I should just change the cables for some ready made ones of the correct impedance with SMA connectors?

I’ve also been reading up about antennae again and I’m wondering whether the FA (or similar) would suit my location because, like many people, I have trees and houses blocking my view of the horizon in most directions.

Thoughts very welcome…

The better the antenna the better the chance you might still get some signals through the trees.

Yes but doesn’t the FA have a very flat reception pattern?

Well you are going to be receiving the aircraft above the trees anyway because they are closer and the signal is much stronger.

Very true.

Any thoughts on cable?

Do you think the LNAs would compensate for any loss in my imperfect cables?

Yeah i would replace the cables last if at all.
After the LNA the cables would need to be very bad to be relevant.

Thanks, you have been very helpful as always.

The FA antenna is omnidirectional, that means, it’ll receive poorly from all directions, if not properly sited and installed.:wink:

Go higher, young man. :grinning:Then it’ll receive great from all directions.

Experimentation is half the fun, but if you are not so inclined, the FA antenna is one of the best values out there.

Since you already have an RTL-SDR Blog V3 dongle, their LNA/Filter combo is a natural.

Yeah, I built various antennae of different types about four years back and kept the one that worked best. There’s only so much I can do because I can’t fit them outside unfortunately so they’re as high up as they can go under the ridge tiles.

I got a couple of RTL-SDR Blog LNAs when I bought the V3s but hadn’t had a chance to try them out until today.

I altered the cabling and installed them in the loft this afternoon. One of them works but unfortunately, the other one does nothing to amplify the signal. Problem moves between SDRs / antennae with the LNA so it must be faulty.

Preliminary results look promising. Need to tweak the gain for best results over the next few days.

But it let’s signal through?
Normally if they don’t work they block all signal.

Write them a mail they should send you a replacement.
Heard of another case recently where one of their devices was bad.
QC seems to be a bit lacking but if they work they do great.

I sent them a message last night and they have asked about bias-t.

On each Raspberry Pi, it passes signal without any improvement when I enable bias-t. If I turn off bias-t, I get no signal at all.

The problem moves from Pi to Pi when I switch the LNAs.

No improvement? That seems odd.
How do you tell it’s no improvement?

Change the gain to 23 and compare between both LNAs then.
(23 is a reasonable starting point with your combination of dongle and LNA)

You then can compare the mean signal strength in the graphs then (green area)

Are they both the filtered version or did somehow an unfiltered version get mixed in by shipping? (Should be printed on)

Do you swap over the adapters with the LNA, then it could be one of them.

The LNAs were bought at the same time and are identical.

I initially forgot to turn off AGC when I first installed them.

One Pi gave me a solid horizontal line above the red line at the top of the graph and 25% signals > -3 dBFS.

The other Pi gave me exactly the same signal I’ve had for the last couple of months.

When I turned the gain down to 30, one Pi gives me the worst signal levels I’ve ever had and half a dozen planes and the other one gives me the best signal and more planes than I’ve ever had.

I shut down the Raspberries, went in the loft and swapped the LNAs over and the situation reversed.

That’s quite convincing then.

Hopefully your replacement will arrive soon.
At least you have one to work with :slight_smile:

Yeah. Because I’m running two Pi, I bought the two V3s and two LNAs at the same time.

I have a house slightly higher and at right angles to mine. Their roof runs north-south and their ridge is centre line of my house. Coincidentally, there are some trees on the other side in almost the same position.

So I put an antenna right up under my ridge, half way between the centre line and each gable end.

With the two antennae, I get a better aggregate view of the lower part of the sky on VRS than I could hope for with one. I’m not really ready to splurge on ready made antennae yet.