Help understanding costs of acoustomagnetic systems

Discussion in 'Wireless & RF Design' started by OneJeremias, Nov 23, 2012.

  1. OneJeremias

    Thread Starter New Member

    Nov 22, 2012

    I've got a bunch of questions about acoustomagnetic technology that I can't seem to get definitive answers for online. I sort of understand how it works, but the lingo used in many articles is sometimes confusing, so I'm hoping someone here can simplify things for me. I apologize in advance for leaving out any critical information, but please just ask and I'll provide whatever you need, as long as I have the answer!

    Transmitter: There's a radio, and an antenna, and most acoustomagnetic systems use a 58khz frequency send out in pulses, but that's about all I know. What would I do to put a simple one together? Where would I look for a radio? Can I just buy one that's capable of that frequency, and hook it up to an antenna? Are there other components and materials involved? Does the radio have to be special in some way to handle pulses vs. a continuous transmission? And if the range only needed to be 3 feet or so, I'm guessing it wouldn't need a very powerful / expensive radio?

    Receiver: It would seem this is simply another radio and antenna, which will detect the response frequency of the tag that goes through the detection field. Is this the case? Most of my questions above would apply here as well, with the addition of the following: what is required to determine if the response is at the right frequency, and to determine what action to take when that happens? Is that component easily purchasable as well?

    A few extra questions: Is there a reason 58khz is used? Is it easy enough to change the frequency used to something else, like 50khz? If one were built using that frequency, would it be enough of a difference from the retail EAS systems to prevent false alarms if a 50khz tag went through?

    My main goal here is to figure out if it's possible to build a simple example of one of these, and how much it might cost to do so. I would especially be happy to know if the cost changes if I wanted to use a transceiver instead of a separate transmitter / receiver setup.

    Thank you in advance!
  2. vk6zgo

    Active Member

    Jul 21, 2012
  3. OneJeremias

    Thread Starter New Member

    Nov 22, 2012
    Thanks vk6zgo, not sure why I didn't receive an email to let me know you had replied, so sorry this is so late.

    Those articles were quite helpful in my initial investigation into this project, but what I'm really trying to figure out is whether the components are prohibitively expensive, or if one could be built for as little as $100. As I said, I'd like the range to be only 3 feet or so, and the antenna only needs to be about 2 feet wide.

    I realize I'm asking a lot here, but I wonder if someone would be willing to find examples of the parts I would need and point me to them here? Thanks again for your reply.