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Anyone know how I can build a FM radar gun?

  1. Jul 5, 2010 #1
    Well here are a couple of things I would like to know. Thanks in advance!

    how to build a Frequency-Modulated Radar gun.

    or how to build a Frequency-Modulated transmitter and reciever

    or where i can get either of these :D Thanks again!
  2. jcsd
  3. Jul 6, 2010 #2
  4. Jul 6, 2010 #3


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    Staff: Mentor

    Welcome to the PF.

    You can get small FM transmitter kits from electronics stores like Radio Shack, or from online electroics kit suppliers. They are designed to put out a small enough signal to allow them to pass the FCC rules. You can pick up their signal on a standard FM radio receiver, usually up to 10m or so away.

    To go with higher power than that, you need to have an FCC license.
  5. Jul 8, 2010 #4
    well I plan to use this FM thing for a radar gun so can someone explain to me how I can make it into a radar gun? I need the FM transmitter and reciever because i plan to move while using the gun and want to know both the distance of the target and the speed of the target. Thanks any details on my plans are appreciated.
  6. Jul 8, 2010 #5
    The easiest way to do that would be to transmit pulses to the target. The distance can be calculated from the round trip time of the pulse. The velocity can be calculated by dividing the change in distance between consecutive measurements by the change in time between the measurements.

    It sounds like you need to do a lot of research about radar and microwave circuitry before beginning a project like this.
  7. Jul 8, 2010 #6
    I have done my research on Radar so I know that I need something like a FM transmitter because doppler radar can not measure distance.

    But why would I need to learn about microwave circuitry?

    Also can you contain a link on where I can learn more about microwave circuitry?

    Thanks, much appreciated.
  8. Jul 8, 2010 #7


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    Staff: Mentor

    Say what?

    Have you done much reading about radar? You should be able to tell us...

    You can start learning basics at wikipedia.org



  9. Jul 8, 2010 #8
    Berkeman, I had to laugh a little at the Wiki link to radar where it describes the P band "for 'previous', applied retrospectively to early radar systems". The U.S. Navy is currently operating a SPASUR (for space surveillance) Radar system on about 217 MHz.
  10. Jul 9, 2010 #9
    hahaha, my bad I read it wrong. Indeed I guess i do need to learn more about radar as i have been only learning about radar that deals with my project.
    Thanks all!

    I misread the "micro wave" thing as wrong. I thought you wanted me to learn about the circuitry of a microwave that heats items. :redface:
  11. Jul 15, 2010 #10
    FM TX is easy to build ...smallest FM TX can be built around BF194 transistor...ckeck net for circuits

    FM RX is little complex...i think u can but compact receivers with auto tuning ...china make will be cheap

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