8ohm to 4ohm Preamp Mic Schematics

Discussion in 'The Projects Forum' started by Turbo_Boss, Oct 24, 2008.

  1. Turbo_Boss

    Thread Starter New Member

    Oct 24, 2008
    2
    0
    Hello guys,

    I fly ultralights and I have a Comtronics Headsets with Dynamic microphone that I have conected to a Handheld Radio. THe problem is that I hear other people buy nobody hear me.

    I have talk with many people regarding this problemo and they toll me that the Comtronics Mic requires some sort of amplification because is 8ohm and the Handheld radio only works with a 4ohm Mic.

    Comtronics ask for this Preamp Patch U$99.00 [​IMG] [​IMG]

    If you check the Comtronics Preamp pic you will see is a very simple gadget with few parts.

    Have any of you has a schematic diagram of this Preamp or a Preamp that can work for my configuration in order to build it myself?

    THX,

    Isaac


    [​IMG]
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
  3. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Here is the circuit you need:

    users.ece.gatech.edu/~mleach/ece3050/notes/bjt/ccamp.pdf

    RL on the schematic represents your radio mic input

    Note: before users.ece........ put http:// for the site to work
    I posted it completely but i could not post my answer with the web link inside

    Why is this moderators?
     
  4. Turbo_Boss

    Thread Starter New Member

    Oct 24, 2008
    2
    0
    Hey Mik3,

    Thank you for the link. I got this schematic in another forum. I have not try it. What you think?

    Thx,

    Isaac

    [​IMG]
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    What does 8 ohm to 4 ohm have to do with preamps? That is normally only a question for audio power amps.
     
  6. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Every dynamic mic that I have seen is 600 ohms.
    Maybe this one uses an 8 ohm earphone as a mic.
     
Loading...