HOWTO: Airspy mini and Airspy R2: Piaware / dump1090-fa configuration

[wiedehopf]

@keithma

at the whiff of RF that I’ve experienced.

The transmitter in his case is probably more than a km away and you were transmitting from the same pole

Compared to usual interference, the “whiff of RF” you describe was probably 20 dBm more

[keithma]

@wiedehopf

The transmitter in his case is probably more than a km away and you were transmitting from the same pole

Well nearby.

Hey, I didn’t suggest it, I was only clarifying what I meant.

[iandrews]

@caius

Yes you will almost certainly see a dramatic increase in messages and aircraft. The airspy is far more capable than the rtl dongles.

I’ve never see more than 1800 msgs/s with 1600/s being more typical. The airspy regularly gets around 3000/s. I’ve seen over 400 aircraft simultaneously with the airspy.

Hope so, at busy times I do push 2000 msgs/s / 230 aircraft, but I do seem to be missing far off planes, and my max range is about 240.

@caius

I think waiting to see what performance you get before cutting the coax is probably a good plan. You might find it’s not too much of a problem, though getting the amp as close to the antenna as possible is ideal.

Yes, going to wait and then evaluate.

@caius

Sell it and get the rtl-sdr.com triple filtered one instead. The filtering on the current version is not as tight as the original, but it should still be good enough. I’ve been using one for a couple of years and it’s performed very well. It also has higher gain than the uptronics amp.

Was thinking that, but again, I may just wait until the Airspy arrives.

@caius

You might find this thread interesting for seeing where your signal is getting blocked if you haven’t seen it already: Signal Strength Heatmap

Tried setting this up, run into a few issues, posted on that thread.

Thanks for you help.

[keithma]

@iandrews

Hope so, at busy times I do push 2000 msgs/s / 230 aircraft, but I do seem to be missing far off planes, and my max range is about 240.

240 is about the maximum you’ll get under flat conditions.

[iandrews]

So, the Airspy mini arrived (Direct from ITEAD in China, ordered last weekend, posted Monday, arrived Friday lunchtime).

I swapped it with the orange dongle on one of the pi’s, and ran the install script for airspy_adsb, and then ran the Graphs1090 install to update the graph files.

Also, noticed that the default options had CPU at 60 and a upper limit for the preamble at 20, so changed that to one mentioned a little bit above to:

OPTIONS= -v -t 90 -f 1 -w 5 -P 8 -e 10.0 -C 75 -E 60

(This is currently running on a pi 3B (not +)).

All seems to be working ok, using tar1090 / graphs1090 message rate is up, estimate about 20-25% over the Blue dongle, however Total Aircraft is about the same (but with positions is maybe slightly less).

Stats on the FlightAware site for today (up to 09:40) show:

Dongle, Positions, Planes
Airspy, 274039, 1604
Prostick Plus, 261080, 1606

So, though it’s pulling in more messages, it’s not transferring into (m)any more planes.

I am planning on replacing the 3B with a 4B, so not sure if that will help with plane count, but any other suggestions on settings to use, or changes to make (apart from getting LNA closer to aerial, or swapping out current LNA with the rtl-sdr.com one.

(also ran some frequency scans on a PC with the now spare orange dongle, to see what difference a filter would make, so have added to the filter thread).

[foxhunter]

@iandrews

So, though it’s pulling in more messages, it’s not transferring into (m)any more planes

That is the result of my investigation as well.
I compared it with my AirSquitter i am running.

The number of Messages is approx 5% higher but the number of registered aircraft is the same.
Well, if there aren’t any more aircraft due to my environment there aren’t any

Note: The AirSquitter is driven with an Uputronics in Front of it. Otherwise it would have a lower detection rate.

However if you ask me for a rating it would look like this:

1. Airspy
2. Airsquitter/Radarcape
3. Flightaware dongle

[iandrews]

@foxhunter

Well, if there aren’t any more aircraft due to my environment there aren’t any

Yes, starting to wonder if I’m at my limit, theoretically there are more planes around me (as other nearby sites are picking up more), however, maybe due to line of site issues (roofs / trees etc) maybe I just can’t get them.

[foxhunter]

@iandrews

as other nearby sites are picking up more

Even if the site is close to you, it’s hard to compare. There are too many individual things which can differ.

I know that i am at my limit from the range based on environment. So the improvement by using an Airspy is not as much as for others in a rough environment

[wiedehopf]

@iandrews

So, though it’s pulling in more messages, it’s not transferring into (m)any more planes.

Plane count never changes by really large numbers with adding the airspy.
Especially if limited by terrain.

https://github.com/wiedehopf/tar1090#heywhatsthatcom-range-outline

[iandrews]

@iandrews

Yep, thanks. I have a haywhatsthat range ring. As the above pic shows in some areas I’m not far off it. But in others, such as south / south west, I am a little lacking. I was hoping the Airspy would help pull in some from those areas.

[triggers]

@landrews How long have you had the plot running? Air traffic changes direction day to day and week to week. Some weeks I get a lot of traffic from the NW and other times from the South. Let it run for a couple of months then take another look.

[wiedehopf]

@iandrews

. As the above pic shows in some areas I’m not far off it.

Yeah line of sight is hard to overcome.

I don’t suppose you can sit next to your antenna and take a look.

[iandrews]

Funny you should say that, the other day I put my phone on a stick attached to a long pole, and got this leaning out a window!!!.

https://share.icloud.com/photos/073t3K93FsRtO4sdJjkbXufrA

Phone / camera about the bottom of the areal. Starts off looking about south west, when you can see the aerial it’s about west, chimney stack north, and then continues round.

[iandrews]

@triggers

How long have you had the plot running?

That’s probably just a few days, however similar too if it’s left to run for a while.

[keithma]

@wiedehopf

I don’t suppose you can sit next to your antenna and take a look.

@iandrews

Funny you should say that, the other day I put my phone on a stick attached to a long pole, and got this leaning out a window!!!.

Definitely some things in the way there, can see why you’re getting blocked in some directions.

I strapped a phone to my mast back in 2013 which was a bit higher than the ADS-B aerial and put a video up on YouTube here. Note the huge tree blocking my view to the east.

Then last year I got a drone and did another video that you can see here, this time from about two feet higher than my new ADS-B aerial position. You’ll see that the tree to the east has completely gone

[iandrews]

Great view, and nice and flat.

I replaced the Uputronics LNA with the rtl-sdr one yesterday (surprised how small the rtl-sdr one is). Enabled bais-tee on the airspy and straight away noticed a slight jump in aircraft, however the messages was down by about 400 on both the airspy and prostick plus.

Now, seeing as I have a splitter (and reading something here recently) I thought that the bais-tee voltage as well as going to the LNA was also going back down the chain to the prostick plus.

Removed the splitter so it was just aerial → rtl LNA → airspy and the aircraft stayed about the same, but message rate went back up.

I have ordered a small bais-tee power injector so that I can have that powering the rtl LNA before the signal splits, but for the time being I have the original Uputronics LNA, then splitter then have the rtl-sdr LNA just before the airspy. Doing this the gain on the airspy has been reduced down to about 9, but I think message rate is up a bit, but plane count is clearly up, maybe by about 10%.

Will see what just using the rtl LNA does, but I had a look yesterday, and I think I can cut the cable just below the mast, and attach some SMA connectors and get the RTL LNA up there so the signal is boosted at 3 meters rather then 15.

[butterfly2]

The RTL-SDR supplies a higher gain output, did you adjust (lower) the SDR gain to adopt the newer RTL-SDR gain? That might clarify why you where missing the 400msg/s due to oversteering the AirSpy input.

Good to hear that your got a 10% increase in planes, that might due to the double SAW filter in the RTL-SDR compared to one in the Uputronics.

Im interested if you can do a compare, with graph1090 pictures? The founder of AirSpy once wrote that he achieved incredible results with the AirSpy combined with the Uputronics.

Best way to compare is when the LNA is at his new location upon the mast.

[foxhunter]

@butterfly2

results with the AirSpy combined with the Uputronics.

That is the combination i was running for a while. But Uputronics offers two different filters as far as i know, there is another one as “ceramic” filter. Not sure about that and the performance.

So far Uputronics does not offer it on their website, maybe they stopped it.

[butterfly2]

That is the combination i was running for a while. But Uputronics offers two different filters as far as i know, there is another one as “ceramic” filter. Not sure about that and the performance.
So far Uputronics does not offer it on their website, maybe they stopped it.

True, RTL-SDR’s LNA has also different types of filters is Google telling me.

[Dutchyb]

@foxhunter

So far Uputronics does not offer it on their website, maybe they stopped it.

On his website:

Since March 2020 we have fitted improved SMA female connectors for antenna input and radio output to address the issue of the SMA barrels coming away. Also the Bias Tee regulator kit is now fitted as standard. At this time a ceramic filtered version of this unit is no longer available.