FRS foxhunting for model rockets


Since we had a FRS radio hackit a while back, [Weirdguy] sent this in. [Scott] gutted a frs radio and added it to his rocket chassis. It’s powered on for the flight, and he can listen to the rockets progress. To locate the rocket once it’s on the ground, he built a 462Mhz Yagi antenna to use with a Radio Shack hand held scanner. This is old hat for most Ham Radio guys – they do ‘Fox Hunts‘ for hidden transmitters just for fun.

10 thoughts on “FRS foxhunting for model rockets

  1. Some types of antennas look just like a cross, with wires strung in a flat coil. I’ve heard an old story told where a fellow was pulled over by the police during a fox hunt. An elderly woman had complained about a madman driving up and down her straight waving a cross out of his car’s window :)

  2. Not to put too much of a damper on it, but do you realize how many FCC regulations are being violated with this hack, not to mention radio etiquette with the continuous transmission? You really should read over the section of the FCC regs for the family radio service before making mods of this nature… especially with the public posting… Nice work on the receiver antenna…

  3. this is pretty “old hat” for Rocket guys as well. we’ve been doing various radio tracking schemes for quite some time now. nothing sucks more than a lost rocket.

  4. Actually, im not sure that and regulations are being violated. Mabe the modification to the radio, but its only .25W, so its not likely to cause much interferance. and on that note, the frs radios are so crappy anyway that its not like anyone will be complaining.

  5. You could use a timed recording to trigger a VOX circuit.

    I did something similar when I did some rage tests with a set of FRS radios.

    I used a Palm Pilot with a Morse code tutor app set to send my call sign but with an extremely long pause before repeating.
    I then simply placed my Palm pilot next to the VOX-enabled radio and bingo! Instant beacon.

    I was able to drive around with the other radio and get an idea how well the signal got out and at what distances.

    The beacon thing would work well for this application.

  6. The FRS band radios are a bit more strictly regulated than people think. Though less restricted than CBs. Specifically
    http://a257.g.akamaitech.net/7/257/2422/16nov20071500/edocket.access.gpo.gov/cfr_2007/octqtr/47cfr95.193.htm
    details communications allowed on FRS bands. Section A specifies that communications must be between persons. I remember reading in the past that someone had set up their PC with voice recognition software, and some text to speech tools, so that they could speak commands to it via an FRS radio and have it read back information. As one side of this FRS communication didn’t involve a person the FCC smacked the guy with a fine.

    The other FCC rules basically ban you from doing internal mods to an FRS radio, or boosting it’s output power / antenna gain. Supposing he simply swapped the guts of his radio into a new chassis it *might* pass muster, but if he tweaked anything while doing so then he’s screwed.

  7. Thanks for the link to my blog….

    I’m not really familiar with FRS regulations, but one way to ensure that you’re not violating them is to get an amateur radio license and use amateur radio for this kind of project. Last February, the Morse Code test was eliminated for all classes of licenses, and it’s relatively easy to get a Technician Class license. Cerainly any of you doing hardware hacking could pass the test with just a bit of study.

    To make it even easier, there’s a free study guide on my blog, http://www.kb6nu.com/2006techstudyguide.pdf. If you’d prefer a printed version, you can purchase one by going to http://www.booklocker.com/books/3408.html.

    Let me know if you have any questions……73, Dan KB6NU

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