KGRR Setup

After 1 month of testing, I think I have found the best setup I can get. Components as follows:

rPi 2
NooElec SDR Dongle
FlightAware Antenna
Alphaline Amplifier - SEA-100

Dump1090-Mutability with settings of AGC and gain== -10
Maintenance script reboots the rPi at 2AM when there is the least amount of traffic and I run another script to reboot the rPi if the network connection is broken.

Between the amplifier and the AGC & Gain==-10, my average range jumped 70 miles to now consistently picking aircraft 120miles + out. The downside is that my CPU usage went from 18% to 31%. The HeyWhatsThat circles seem to not be real accurate for my location as I very rarely pickup anything outside the first path which is set for 10000’.

http://s1.postimg.org/8t4m7yhjz/Capture.jpg

You might want to try a satellite in line amplifier to see if it improves things.

Your Alpaline amp is designed for over the air tv in a lower frequency band.
It may - or may not- be providing the desired amplification at the higher 1090 frequency.

The 1090 frequency is within the satellite inline amplifier frequency band.

Thanks. It’s what I had laying around and others have used it here with success. I’ll be on the lookout for a more appropriate amp, but I need to make sure it is at the right price.

You can try a few things - test the gain set at max rather than -10. I found that it gave better results.

You are using a VHF/UHF amplifier, which is definitely boosting signals that you don’t want into the dongle. Depending on what transmissions there are near you, that could easily overload the front end of the dongle and reduce reception since they aren’t very selective. As elpipila says, a satellite amp is better suited since it won’t boost the lower frequencies. Adding a filter might help - either the flightaware one which is specific to 1090MHz, or something like a satellite/UHF diplexer acting as a high pass filter. If I take my filter out I see big reduction in range and messages received. You could try using rtl_power to see what other transmissions could be affecting you. This thread has details on how to do it: ads-b-flight-tracking-f21/filter-not-producing-desired-result-t36540.html

Both satellite amps and diplexers are dirt cheap on ebay, so it’s worth having a look there.

The flightaware antenna is pretty good, so you should be seeing better results than you are, but it’s important to give the antenna an unrestricted view of the sky - if it is inside, try putting it in the loft, but better is to have it mounted outside as high as possible. Surrounding buildings or trees can obstruct the signal and reduce the range considerably.

Posted Image link because I just can’t figure out how to get the correct link to the picture on here using the IMG tags

Been there, done that.

This link will give you the instructions for creating the proper URL to use in the IMG tag.

http://blog.appsevents.com/2014/04/how-to-bypass-google-drive-viewer-and.html

I’m working on a batch file that will do this with the sharable link on the clipboard. The comandline device, CLIP, is write only. Getting data from the clipboard involves some trickery. Now that the busy holiday season is behind us, I’ll have more time to work on this little project. Will post it here when it is finished and working reliably.

I figured out that this was the easiest way PostImg

Unrestricted is a slight issue. I currently have the antenna 35’ AGL, but I am in a bit of a hole and would need an additional 30’ to get over top of the trees. I think the trees (even without the leaves) are causing the biggest issue.

Here are some quick & dirty results from RTL_Power. Not sure why the frequency labels are missing, but you can see where the 850 and 1090 are

http://s19.postimg.org/xmcew7br7/low.png
http://s19.postimg.org/am5rjvdxf/High.png

Thoughts?