Signal amplitude of electret microphone

Discussion in 'General Electronics Chat' started by wql, Jan 6, 2011.

  1. wql

    Thread Starter New Member

    Jan 6, 2011
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    Hi guys,

    Just wanna to ask what is normally the signal amplitude of a electret microphone that can be pump into the COTS transceivers?

    Thanks

    Regards
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    Do you need the output level of an unamplified mic, or the proper signal level for the tranceiver input?
     
  3. wql

    Thread Starter New Member

    Jan 6, 2011
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    Ya it will be a suitable signal amplitude into the external MIC input of the transceiver. I will be pumping in signal generated by the signal generator.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    You only get a few millivolts out of a microphone. You are going to need to pad the signal down quite a bit.

    Life might be easier if you have a line level input. That is on the order of a volt.
     
  5. wql

    Thread Starter New Member

    Jan 6, 2011
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    But if I am setting my signal generator amplitude to its lowest which is 50mV, is this value still too large for a transceiver MIC input?
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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  7. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    You can run signal from signal generator through the voltage divider to get smaller signal you want. Lets say you have 50 mV, if you make 100 Ohm and 1 kOhm voltage divider, then voltage across 100 Ohm resistor will be 4.5 mV.

    I have used this method in laboratory experiments. I would suggest to start with some relatively large voltage that the generator can produce reliably, a couple of volts for example. Then run it though voltage divider to get the signal you want.
     
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