Reddit reviews ADS-B Dual 978 MHz + 1090 MHz Band-Pass SMA Filter
We found 6 Reddit comments about ADS-B Dual 978 MHz + 1090 MHz Band-Pass SMA Filter. Here are the top ones, ranked by their Reddit score.
1090MHZ ADS-B / Mode S FilterSMA Female to SMA MalePasses range 980MHz - 1150MHzReduces RF noise, increasing number of ADS-B/Mode S messagesIdeal for RTL-SDR USB Dongle receivers like PiAware
Answers to the common questions.
How did you get this?!
Several RaspberryPi2's (an OrangePi in the mix as well) with DigiTV USB dongles with the R820T2 chip, Low Noise Amplifiers powered by the 5V rail on the Pi, 1090Mhz Bandpass filters, and a mix of commercial and home made antennas tuned to 1090Mhz.
How is this legal?!?!?!!?! Im calling the cops!
The location data is transmitted from each aircraft, in clear text, unencrypted over the air. This includes general aviation, commercial, military and government. I see the FBI signaling they need more donuts with N906TM all the time and the occasional airborne tech tests out of Hanscom. More information on ADSB: https://en.wikipedia.org/wiki/Automatic_dependentsurveillance%E2%80%93_broadcast. I also feed the data out to several places who in-turn use it to let you know if your connecting flight is going to be on time. (I get top teir $$$$$ access to their systems for free for doing so)
There is a lack of air traffic to the south east where aircraft are on approach to Logan.
I know, building blocking that part of the sky, I loose them 6,000ft and under.
Do you have more than one week of data?
Yes, a little over 2 years worth.
Can I have it?
No. But I may post a heatmap every now and then along with the data file used to generate it.
Is there a way for me to see this live?
Yes.
Sites that filter out military/governement/any corporation that asks: FlightAware.com
Live data sites: ADSBExchange.com - PlaneFinder.net - FlightRadar24.com
Why?
Hobby #492843.
As promised, here are my sourcing links:
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The rest of it is pretty standard stuff, Raspberry pi, misc hardware from any local hardware store etc...
Antenna location is king. Getting the antenna up high and out in the open is going to be the best thing that you can do. The signals from the airplanes are quite powerful, so even a modest antenna in a good location will perform quite well, but they don't penetrate obstacles for crap, so no antenna is going to help you if it's indoors or its view of the sky is obstructed.
As far as your antenna options go...
The stock RTL-SDR antenna cut down to a quarter wave of 1090mhz and stuck onto a suitable ground plane will perform decently
You can take a crack at constructing your own collinear antenna. This is what I used for a long time and it was a good performer. Very cheap to make out of some scrap coax and PVC.
Lastly, you can purchase a commercially made ADS-B antenna. This is my current solution and works very well.
If strong out of band interferance is a problem, you can look into an ADS-B bandpass filter.
You could also look into upgrading the RTL-SDR for one customized for ADS-B reception.
edit: A properly optimized setup with a decent antenna should have no problem tracking planes at cruise altitude out to a distance of 150 miles or more..
I can only comment on my own experience, outlined above.
If it's true that my discone is not very good above 900mhz, then perhaps you will have even better luck than me with the proper antenna!
Another thing you could try is a bandpass filter to kill signals outside of the 1090 range you want. Something like this: http://www.amazon.com/ADS-B-1090MHz-Band-pass-SMA-Filter/dp/B010GBQXK8/
Or more specifically, Pi24 or PiAware running with a FlightAware Prostick Plus and an ADS-B filter on what is most likely a Raspberry Pi 3.
Thanks for the link! I found this on Amazon: http://www.amazon.com/ADS-B-1090MHz-Band-pass-SMA-Filter/dp/B010GBQXK8/
Will it do the same thing as the ebay link?