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Ever wanted to eavesdrop on what those lofty control towers in the sky are chatting about? Well now’s your opportunity!

If our previous project seemed a bit daunting, our latest Weekend Project, the Aircraft Band Receiver, couldn’t be easier! With only a simple analog-tuner pocket radio, some batteries, and a couple of small screwdrivers, you can have your own Civil Aviation Band FM receiver.

You see, standard radios, like the one in your vehicle or my decades-old Walkman, range from 88 to 108 MHz. But the FM radio band extends much higher, with the Civil Aviation Band (sometimes referred to generically as the Airband) ranging from 108 to 138 MHz. It is in this range where you’ll find your municipal airport’s air traffic control tower chatter. The equipment used to dial in to the hundreds of channels in this range is typically bulky, and expensive. But with a few modifications to some easy-to-find components inside every analog FM receiver, you can effectively increase the range of your device and pick up radio that is bouncing all around you that you’ve never heard before! Once you’ve correctly re-tuned your pocket radio, you should be able to easily dial in your local airport’s ATIS (typically between 108-118 MHz). This channel is easy to find because it’s constantly looping prerecorded information such as the weather.

Watch this video by the venerable Kip Kay to see how simple this project is. And send us some photos from the field of you with your successfully modified Aircraft Band Receiver – be sure to include the air traffic control tower in the picture!

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See all of the RadioShack Weekend Projects posts (to date)

Nick Normal

I’m an artist & maker. A lifelong biblioholic, and advocate for all-things geekathon. Home is Long Island City, Queens, which I consider the greatest place on Earth. 5-year former Resident of Flux Factory, co-organizer for World Maker Faire (NYC), and blogger all over the net. Howdy!


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Comments

  1. Roy says:

    I’m surprised this works, as air band communications are via amplitude modulation (AM) whereas FM radio is frequency modulation (FM).

  2. Roy says:

    I’m surprised this works, as air band communications are via amplitude modulation (AM) whereas FM radio is frequency modulation (FM).

    1. Anonymous says:

      thanks for the update Roy! I was already researching the phenomenon before your comment, but that’s a good forum you found there.

    2. Peter Simpson says:

      AM is fairly easy to demodulate, easier than FM.  Assuming the cheap transistor radio is using something like slope detection for the FM, it would demodulate AM as well…except it would be noisy, because the FM signal is much wider (200 KHz vs 20 KHz) than an AM signal.

      All you really need to demodulate AM is a tuner, a diode and an amplifier. This type of receiver has the advantage of not using a local oscillator (LO), which could interfere with aircraft systems. There are several designs along these lines: http://www.techlib.com/electronics/aircraft.htm

      //de KA1AXY

    3. Anonymous says:

      Your point is correct. It actually should work tho: older super-simple transistor FM-band bugs were actually AM-modulated with some tradeof with espect to quality and bandwidth. Only with varicap diodes those bugs became really Freq Modulated.

  3. Anonymous says:

    Neat project, my daughter loves watching the airplanes come and go from the airport and we did this mod last night.  Can’t wait to try it out, should make our next trip to the airport even more fun.

  4. Anonymous says:

    Neat project, my daughter loves watching the airplanes come and go from the airport and we did this mod last night.  Can’t wait to try it out, should make our next trip to the airport even more fun.

    1. Anonymous says:

      Great! Take a picture and send it to us, and let me know what chatter you hear!

    2. Anonymous says:

      Great! Take a picture and send it to us, and let me know what chatter you hear!

  5. Anonymous says:

    Neat project, my daughter loves watching the airplanes come and go from the airport and we did this mod last night.  Can’t wait to try it out, should make our next trip to the airport even more fun.

  6. beak90 says:

    This isn’t a new weekend project… Its just a repost from 2008. Make some new weekend project videos!

  7. Anonymous says:

    Damn, I just can not get away from REO Speedwagon.

  8. Anonymous says:

    Damn, I just can not get away from REO Speedwagon.

  9. Anonymous says:

    standing in front of an airport with a video camera and a device that has an antenna.

    man you are brave.  I hear the TSA shoots people on site for stuff like that.

    1. Anonymous says:

      Of course that’s not true. And in fact in countries like England, post-9/11, Airplane Spotters are relied upon to report suspicious activities of aircraft. And spotters have also been responsible for bringing awareness of “extraordinary rendition” to the press in various countries.

  10. cnd says:

    I did the Mars/Cap mod to my Yaesu VX7r, which allows me to transmit on air-band (I’m a pilot), before I realized that the vx7r modulates that in FM. For those who are interested, my AM airband transceiver *can* hear and understand my FM transmissions, albeit only in a very reduced range, and it comes out very quiet. The vx7r receives in AM on that band (even though it xmits in FM), so I wasn’t able to check if an FM receiver can hear AM modulated signals, but at least now you know that the other way around kind-of does work, *just*.

    1. Well it only works the other way around because the AM receiver can use slope detection, but the FM receiver can not detect amplitude variations.

  11. I don’t think it would work unless you remove the limiter, because the hard limiter is designed to cut off all amplitude modulated changes so that only frequency modulated changes exist.
    Unless its a simple pocket radio that doesn’t have a limiter and uses slope detection on the local oscillator. It is possible to use the local oscillator as the slope detector because as the frequency varies away from the tuned frequency it becomes quieter so the amplitude information is recovered.

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