Changed USB Dongle. No data on PiAware Skyview

It might indeed be as Sonic suggested.

Try reducing the gain with

sudo piaware-config rtlsdr-gain 38
sudo systemctl restart dump1090-fa

I just checked http://green-tech.ddns.net:8080/data/stats.json
which shows a very high signal that is always present.

It could also be that with the new antenna electrical noise is stronger than the ADS-B messages because a source of electrical noise is located close to the antenna.

I’ve done as you said. Still no data: green-tech.ddns.net:8080

Most likely electrical noise is the problem.

Can you try moving the antenna or is it already on the roof?

Fitting a makeshift antenna from a piece of wire would be good thing to troubleshoot the problem, something like in this picture:
(Not sure what happened here with my PiAware?)

Then you could better tell if the dongle itself is the problem without moving the antenna.
(I doubt the dongle is the problem because it is obviously receiving something even if it’s mostly noise)

The FA stick has an internal preamp, that’s why I assumed the signal is too high. On mine I had to reduce the gain by 18dB compared with no-name.

Straighten a paper clip and insert in dongle’s input as an antenna.

LE: I see three-four planes now. At night time, the traffic is lower.

Just looked at that greentech web page. There was some data - shown below. So working but not very well?

Edit: Perhaps it is working fine. Looking at FR24 for locations, I saw it picking up targets at 150nm. But a very narrow window. Aircraft over Oradea but for a very short time, Need to consider antenna location.

ICAO Ident Squawk Altitude (ft) Speed (kt) Distance (NM) Heading Msgs Age
471F78 Flag 5650 28,575 ▼ 398 120.8 304° 52 18
885176 Flag THA917 32,975 512 135.1 114° 107 27
8960CD Flag 4721 35,000 64 2

That’s his other dongle i believe :frowning:
(the stats.json i checked has much lower signal and noise reading than with the other setup)

OK , I assumed that was what he was referring to. Even the “other” dongle has a very limited window of view.

Yes You are right. I switched back to my old dongle.

Flightaware Pro Stick Plus works fine. I’ve tested with a linux distro/dump1090 and basic “antenna”. I need to check my Flightaware antenna and cable now. Thanks.

I wouldn’t call that working fine and the wire you stuck in was too long, should be 6.8cm :slight_smile:

Anyway to me it looked like the antenna is working fine, it just picks up strong noise that overloads the amplifier or receiver in the blue dongle.

You could do a scan for noise like described here:
(Do I Need A Filter?)

For that just connect the blue dongle to the antenna how it is installed.
Use a gain of 35 for the spectrum scan.

As for filters there are multiple available.
The round blue filter sold by FA is one option.
Or you can try one from Hong Kong, this one for example:
(https://www.ebay.de/itm/1090MHz-ADS-B-Passive-Bandpass-Filter-BPF-Software-Radio-Software-Radio-SDR/253735059773)
No guarantees, if the filter does what it says it is good but you never know on ebay :slight_smile:

Best filter in my opinion is this:
(New Product: RTL-SDR Blog 1090 MHz ADS-B LNA)

But you need a bias-t to use it, so you need additional stuff.

1 Like

It seems I need a filter. Here is my scan. FA ProStick Plus + FA Antenna. Gain 29.7

If that scan is correct even a filter can’t help you.
Somehow you are getting strong noise from 1060 to 1120 MHz.
(The filter can’t filter 1090 MHz and a little bit around that otherwise it will filter the airplanes as well)

The only question is where the noise is coming from because it’s obviously less of a problem with your indoor antenna.
Maybe the cable is going by some very strong RF noise?
(That much noise would mean somehow the coax you are using is not shielded properly)

I suppose you could use gqrx to display the spectrum/waterfall live, tune for 1090 MHz and move around with your laptop and walk around a bit, maybe you can make out a source.
Or walk around with the FA antenna.

Apart from that you might have noticed additional to the options for filters from my previous post, FA is selling a new filter (which is better than the old one): Announcing the new 1090 MHz only bandpass filter!

I’ve just bought the new FA Filter. Waiting to arrive…

1 Like

There is no filter to help with that noise around 1090MHz, if that graph is correct.

But I don’t know of any source like that around Baia Mare (the military unit next to you is not a radio/radar one), I am wondering if that noise is originating in your equipment (dongle, power supply).

1 Like

Hello again. Could you advise me in buying an antenna cable. I think the cable is the problem. I need a short cable 3m, SMA Male - N Male connector. I am using now 3m - YangYang 50 Ohm RG58 coaxial cable.

This: For Beginners - Howto Connect FlightAware Antenna, Filter and Pro Stick - Connectors and Cables Required

describes the different cable qualities recommended. I’m not quite convinced the cable is your whole problem. You could do another scan with your other dongle at a gain of 49 with your old antenna and check how the noise looks there.

Anyway i’m not sure which shops you have access to, so the linked thread should give you a good variety of good cables.

1 Like

I am sure it is the cable. I found that I can find a position of SMA Connector (not screwed all the way) that increases significantly reception. That data is from last night. Today I’ve lost it again.

1 Like

Removing the ice around the base of your antenna might help too…

1 Like