Converting Broadcast radio to ATC receiver

Discussion in 'Wireless & RF Design' started by MarkL, Jan 6, 2010.

  1. MarkL

    Thread Starter New Member

    Jan 6, 2010
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    First of all, I am a pre-beginner at all this and don't pretend to know the difference between AM and FM, so be gentle.
    I live close enough to BWI airport to monitor the tower, ground control, Patomac Approach and departure as well as some enroute traffic control. Some of my antiques have selectivity that allows me to hear Tower,119.4, and approach on the same radio, but ground control,121.9, is a stretch, and requires a second radio. enroute and departure would require additional radios to monitor them all, although it would get pretty busy. Can an FM radio, 88 - 108, be re-tuned to receive the air band, 108 - 133? I was searching on eBay the other day and saw an ad "CONVERT YOUR RADIO INTO AN AIRCRAFT BROADCAST RECEIVER". For six dollars the author will impart his knowledge and wisdon to me. I'm afraid the wisdom will be to go buy another antique receiver. I wouldn't want to spend six bucks on that. Over the years I've been told that aviation com. is AM even though the freqs. are in the FM range. Maybe you can see where I get confused. If it's a matter of sticking a screwdriver in an "IF can" I may be able to handle it. If I have to take nail clippers to a winding, I'm gonna need a partner. My bet is someone out there knows and is patient enough to tell me.
     
  2. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
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    Easier just to buy an aviation receiver. Radio Shack used to carry lots of them before the internet became popular :)
     
  3. MarkL

    Thread Starter New Member

    Jan 6, 2010
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    Thanks, I guess. I take that as a no. Re-tuning is not a solution. I seem to hang on the trailing edge of technology.
     
  4. Wendy

    Moderator

    Mar 24, 2008
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    Actually there is a way, but it is pretty technical. You move the frequencies to the FM band with a down converter. Look up the term heterodyne on Wikipedia.
     
  5. MarkL

    Thread Starter New Member

    Jan 6, 2010
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    As complicated as the Wikipedia article sounded, it is probably understated and way over my head and abilities. Thanks for adding to the explanation. As an engineer you'll understand, 'when you know what you don't know you half way through.' I'm hardly a quater of the way then. heheh I have a feeling Blueroomelectronics had the solution.

    Thanks again,
     
  6. maxpower097

    Well-Known Member

    Feb 20, 2009
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  7. bertus

    Administrator

    Apr 5, 2008
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    hello,

    You could also make a converter using a NE602.
    The oscillator can be 20 Mhz, this will subtract 20 Mhz from the recieving signal.
    So the scale from 88 to 108 becomes 108 to 128.

    Greetings,
    Bertus
     
  8. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Isn't aircraft radio AM?

    John
     
  9. eblc1388

    Senior Member

    Nov 28, 2008
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    AM is used, I was told for another reason.

    With FM, when there is no signal, the noise is unbearable and thus a squelch circuit is needed. This effectively silence the audio output with no radio signal presence.

    Apparently a little bit of noise from an AM radio, with a correctly adjusted squelch level, is more comforting than silence which also happens when the power is off, someone turned down the volume, radio is faulty or whatever.
     
  10. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    The OP wanted ATC communications, presumably just tower and approach based on his location near BWI.

    John
     
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