RTL-duo and Plane Plotter

[Cryptd]

Just thought I would drop this in here.
Just a share, I have no affiliation with either of these programs.

After the local LEO decided it was a good idea to encrypt all of their radio traffic I decided to look into some of the other hobbies I have not played with for a few years.

Namely aircraft tracking.

Looked around on the internet for anything new but just went back to Plane Plotter and RTL1090, then found that RTL-DUO, does that ever work better.
Getting two dongles to talk to each other was a little bit of a pain in the back side, with the RTL1090, at least it was for me.

Seems like the links are all broken for RTL-DUO, but the software seems to be working.
It grabs the first 2 dongles it sees, kind of a pain if using other dongles for SDR as they use different antennas. Probably a way to program the appropriate dongle, I just don't know how.

I used the antenna recipe from here.
https://www.balarad.net/

Am getting close to 250mile range North and East wide open skies. 150miles South and West due to terrain/mountains.

Never know what you might see.

 

[DaveNF2G]

The point of the second receiver is to tune the low-altitude frequency also (740 MHz?).

 

[ATCTech]

Dave, thanks for asking exactly what I was thinking in the OP's screen capture. Two receivers, same location and same frequency didn't make any sense to me either. BTW, 978 MHz is the second low-level (below FL180) frequency assigned for the USA.

https://www.faa.gov/nextgen/update/general_aviation/adsb/

Cheers!

Bob

 

[Cryptd]

The point of the second receiver is to tune the low-altitude frequency also (740 MHz?).

I believe the second is also running at 1090mhz. The first talks to the second dongle, seems to improve the coverage/range. Don't really have to use two dongles, its just better.

They are both on their own DIY 1090 coax collinear antenna using that balarad formula, 2 antenna.

If I forget and have the SDR radio dongle plugged in, one will some times latch onto my Scantenna, really kills the receive. Don't get as many aircraft and probably loose 60-80 mile range.

Example, I missed the fact that I was on the scantenna first pic, second is with both 1090 running, the next day. Day of tracks.

I am out side Bend Oregon, am seeing tracks all the way to Tacoma Washington North and occasionally out to Boise Idaho to the East of me.

 

[Cryptd]

Here is some info.

As far as I know any RTL_SDR dongle will work, they are for TV receive, repurposed with Zadig.

You can get up and running for under $20 for a dongle, can use the whip antenna to get going.
You only really need one dongle to receive the 1090mhz that Mode-S uses, 2 just works better.

Some reading.
About RTL-SDR

Software.
Zadig - USB driver installation made easy
http://rtl1090.web99.de/
PlanePlotter from COAA 30 day free to see if you like it.

I think that's all you need.


Use Zadig to change the dongle driver.
RTL_Duo for the input/receive.
Plane Plotter for the data logging.

Folder should look like this.

 

[DaveNF2G]

The only way 2 dongles would "work better" in such an application is if one is simply a better receiver. With each dongle fed from a different antenna at some multiple of a wavelength apart, you might get some diversity combining. But the dongles do not "talk to each other" through RTLDUO.

 

[Cryptd]

The only way 2 dongles would "work better" in such an application is if one is simply a better receiver. With each dongle fed from a different antenna at some multiple of a wavelength apart, you might get some diversity combining. But the dongles do not "talk to each other" through RTLDUO.

I am not a progamer, just end user, but I can see an obvious improvement running 2 antenna and 2 dongles.
In the first pic you can see a little button maker " Send UDP" clicking sends info to 2nd dongle. As far as I understand.

Like I said, I have no affiliation with any of this software.
Just thought some of you air band listeners might like to "see" the planes you hear.

Try it yourself DaveNF2G if you think I am full of pie.

 

[kma371]

It may just be your imagination. Like the others have said, running the same receiver, on the same frequency, with the same antenna wouldn't improve reception in any way.

Also, if you are using plane plotter, it is recommended you use dump1090 as it supercedes all other old versions of rtl1090

 

[Cryptd]

It may just be your imagination. Like the others have said, running the same receiver, on the same frequency, with the same antenna wouldn't improve reception in any way.

Also, if you are using plane plotter, it is recommended you use dump1090 as it supercedes all other old versions of rtl1090

I only know what I have actually tried myself, without any conjecture or supposed knowledge of how things work.

Try it yourself.

My imagination...please how condisending...and you are mod...go figure.

 

[ATCTech]

I think you'll find a good number of us have been running ADS-B decoding packages for a very long time, myself included. On top of that there are some excellent technical minds here with extensive knowledge. I get that you're just relating what you're experimenting with, but please pay attention to what others are saying. Those of us who have replied to your posts have been down this road already.

I suspect your two-dongle arrangement *may* provide the very limited ability to provide sequential decoding of transponder data a tiny bit quicker than a single dongle/USB connection might, but it can't possibly add to range beyond what Dave has already offered. And as mentioned, those dongles do not inter-communicate.

There are people here who have been feeding various sharing sites with ADS-B data for a number of years as well and I will factually state that my dedicated receiver has been in the top 5 providers in Canada, and typically in the top 125 world-wide, almost continuously since it went on the air in 2014 to the sharing site it feeds.

If I may make a suggestion, why don't you try setting the second dongle to 978MHz and see if you can decode any of the low-level traffic on that frequency in parallel to the 1090 MHz receiver. You may find the number of decodes your display increases substantially.

 

[Cryptd]

I am all for constructive criticism.
I started fooling with these dongles 5-6 years ago.
I tried 1 and 2 dongles, 1 and 2 antenna, little whip, j-pole and then coax colinear.
I run a fast PC.
It is painfully obvious that 2 works better than 1.
Do you guys not see that screen grab, where 1 antenna is the scantenna? Range and number of aircraft received is decreased.

That's fine if no one believes me, I see it works better, probably be even better with 4 dongles and 4 antenna, but maybe that's just my imagination.
Have not tried 4...but maybe I will.
Antenna array, more metal in the air, is that not improving reception?

 

[DaveNF2G]

Yes, more antenna will generally improve reception, but not because it or the software causes the dongles to intercommunicated. The "send UDP" is for connecting instances of the program to each other over a network. It does nothing internally.

You are attributing actual phenomena to incorrect causes. More technical knowlegde will help you to figure out why what you are observing is actually happening.

 

[Cryptd]

Prior to RTL_DUO I had used RTL-1090.
With RTL_1090 you had to add a few lines to the shortcut to get the same effect RTL_DUO does all by it little self.

This...example.
dongle #1 /portbase=31020 /uptarget=31000
dongle #2 /portbase=31000


From what I understand one sends info to the other, improving reception, they are not talking back and forth.
Also with RTL_DUO running and without the 'send UDP' engaged, reception is diminished.

I have not tried to run both coax collinear antenna into one dongle. I could run it like that for a day and see if its just 'more' antenna that's adding to the overall reception.