Building a SDR CTAF monitor. Advice?

Discussion in 'Technical Corner' started by Brad Z, Jan 17, 2017.

  1. Brad Z

    Brad Z En-Route

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    OK, I'm going to get a dozen posts advising me to buy a cheap bearcat scanner for $10 at a yard sale to do this, but I really don't want to do that.

    What I'd like to do is build a "box" with one button that turns it on and off. When it's on it's monitoring the local CTAF frequency. When it's off it's not.

    Reading about homemade ADS-B in receivers this seems like it should be relatively easy to make using a raspberry pi, software defined radio (SDR) receiver, project box, power source and a speaker. Any advice on how to make this project come together, or where I might get help with the software? Seems like it should be simple? Can SDRs receive AM VHF? Do LiveATC feed providers use anything like this?
     
  2. CMongoose

    CMongoose Pre-takeoff checklist

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  3. Brad Z

    Brad Z En-Route

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  4. Unit74

    Unit74 En-Route

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    Buy a $10 Uniden scanner.


    I wouldn't recommend the cheaper Bearcat.:p
     
  5. weirdjim

    weirdjim En-Route

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    I wish to the holy St. Potluck that somebody would write a plain-English version of what the hell they are doing instead of gbbrsh with abbrvtns that only the high priests of the cognoscenti can understand.
     
  6. Joshuajayg

    Joshuajayg Line Up and Wait

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    I used the RLTSDR from my Stratux project to monitor some local aviation bands at one point. They will do it just fine. They have a ridiculously large bandwidth they listen to but that also means they are mediocre at most frequencies. I think a good antenna with a real ground plane will help with reception. I don't remember the program I used to listen to the chatter but it was on my Mac so it wouldn't be the same for a Raspberry Pi setup.
     
  7. Joshuajayg

    Joshuajayg Line Up and Wait

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  8. James331

    James331 Touchdown! Greaser!

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    Last edited: Jan 31, 2017
  9. Brad Z

    Brad Z En-Route

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    Are you referring to my post?
     
  10. RussR

    RussR Line Up and Wait

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    I am also puzzled by his post, which seems to imply that a previous post was full of abbreviations and texting-type spellings, but I don't see any that look like that.

    Well, okay, you did use "AM", "VHF", "ADS-B" and a few others, but those are pretty common acronyms in aviation.
     
  11. weirdjim

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    no, No, NO!!!! Every link that gets posted to how to design SDR radios (including https://github.com/szpajder/RTLSDR-Airband ) is incomprensible. And I've been designing Avionics for sixty years or so. Sorry, I should have been specific. jw
     
  12. slacktide

    slacktide Pre-takeoff checklist

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    Also, the only non-standard term used was SDR, and Brad Z kindly defined that for us in his original post as "Software Defined Radio"
     
  13. GeorgeC

    GeorgeC Pattern Altitude PoA Supporter

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    Brad, did you ever end up building this? I've got an extra SDR lying around that I should put to use.
     
  14. Sac Arrow

    Sac Arrow Touchdown! Greaser!

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    What functionality does an 'SDR' radio give over a standard air band receiver, at least for the OP's stated purpose?
     
  15. Brad Z

    Brad Z En-Route

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    Not yet. I have the pieces but haven't actually done anything with them yet.
     
  16. Brad Z

    Brad Z En-Route

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    I just want a box and a button...no knobs, dials, squelch, etc. I'll admit that it probably doesn't sound like it makes a lot of sense.
     
  17. Harold Rutila

    Harold Rutila Pre-takeoff checklist

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    I would definitely be interested in what you accomplish. I run two LiveATC feeds. I can't say which ones publicly because they sound terrible. People at the receivers' locations, for some reason or another, think it's ok to adjust the squelch, volume, and memory at will, destroying the quality of the feeds fairly routinely. This would be the ultimate solution to that problem.
     
  18. RussR

    RussR Line Up and Wait

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    Get with Dave Pascoe (owner of LiveATC) for information on how to set up SDR boxes if you're having that problem. Most of the frequencies that I serve (https://www.liveatc.net/search/?icao=kokc) are received by a simple SDR into a Raspberry Pi connected to the internet. (Actually, I have three of them which lets me feed many frequencies.) Only the tower frequencies are on an actual scanner (for reasons I can't remember). For the others, there are NO external (or internal for that matter) adjustments available - just a power plug. Seems like it would be optimum for your location.

    Also, @Brad Z , this sounds exactly like what you're trying to do.
     
  19. denverpilot

    denverpilot Taxi to Parking

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    You do know they make boxes you can put things inside of and then lock them, right? LOL.
     
  20. sferguson524

    sferguson524 Cleared for Takeoff

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    That's just crazy talk right there.
     
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  21. denverpilot

    denverpilot Taxi to Parking

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    I still have the scanner that used to feed KAPA TWR/GND. It just sits in a box, bored, nowadays. Ha.
     
  22. Harold Rutila

    Harold Rutila Pre-takeoff checklist

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    Haha I wish I could! Boss man at the location where it is doesn't like that idea because "what happens if the scanner catches on fire?"
     
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