Wireless Intercom Frequencies

Discussion in 'Wireless & RF Design' started by Bill B, Jul 23, 2011.

  1. Bill B

    Thread Starter Active Member

    Nov 29, 2009
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    I am considering a two way wireless intercom system for a project. I'm not sure what frequencies are available for such a device. I want the design to be simple and I plan to use an AM signal generated with an OTA. Does anyone know what frequencies are available?
     
  2. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    27.125 MHz, CB channel 14 used to be used for that kind of thing though most intercoms are FM now.
     
  3. Bill B

    Thread Starter Active Member

    Nov 29, 2009
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    Thanks for the info. Is an FM transmission more practical?
     
  4. Jensen

    New Member

    Mar 9, 2011
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    I believe it mainly depends on which country you live in. For example in USA 433Mhz is the HAM band but is also allowed for short term use by other devices. In Europe they use 900Mhz instead.
     
  5. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
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    I would consider FM more practical for many reasons, among them the fact that it's far less susceptible to interference than AM so it sounds clearer. Virtually all commercial wireless intercom systems use FM. Here's a link that describes some of the frequencies used in the U.S. and Canada for FM intercoms.

    http://www.intercomsonline.com/Choosing-Wireless-Intercom_a/163.htm
     
    Last edited: Jul 24, 2011
  6. Bill B

    Thread Starter Active Member

    Nov 29, 2009
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    Thanks for the link. That was very helpful. I will have to consider an FM transmitter as well.
     
  7. nuckollsr

    Member

    Dec 17, 2009
    16
    1
    You wrote: "I am considering a two way wireless intercom system for a project."

    How did you plan for these 'transceivers' to communicate with each other? Through the air antenna/to/antenna? How about line carrier? Most commercial off the shelf wireless intercoms are not truly wireless . . . they use wiring in the building to conduct the modulated carrier between devices. I think they operate in the 150 to 200 Khz range and use FM modulation.

    Knowing a little more about the physical layout and operational specifications would be helpful. Over what distance do you need to communicate and what, if any, shared power lines connect the two locations. Have you considered the 465 MHz short range handi-talkies?
     
  8. Bill B

    Thread Starter Active Member

    Nov 29, 2009
    61
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    This is for a school project. We have two labs about 100 ft apart and I want to connect the them via intercom. This will be through the air antenna to antenna system.
     
  9. ryangle07

    New Member

    Sep 17, 2011
    1
    0
    can i have the copy of this circuit?.. i just need it for my school project.. thanks.
     
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