Volume control question

Discussion in 'General Electronics Chat' started by FMROB, Dec 3, 2009.

  1. FMROB

    Thread Starter New Member

    Dec 3, 2009
    3
    0
    Hello all, I have a need to control the speaker volume of a two way radio project.

    The radio puts out about 13 watts with a 4 ohm speaker, and about 7.5 watts with a 8 ohm speaker.

    I need to know what size potentiometer to put in line to control volume almost to the zero audio point.

    Right now I am using a 25 ohm 3 watt rheostat and it is not working very well.

    The caveat is I need the control to be small in size.

    Thanks, Rob
     
  2. FMROB

    Thread Starter New Member

    Dec 3, 2009
    3
    0
    Bump to the top
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
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    If you wish to attenuate the output to the speaker, you will need a L-pad.

    Audio volume controls are normally placed at the input of the power amp (or output of the preamp, depending on how you wish to view it).
     
  4. FMROB

    Thread Starter New Member

    Dec 3, 2009
    3
    0
    Thank you for the quick reply, any specific type of L Pad rating?

    Thanks, Rob
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
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    282
    It has to be able to dissipate the power to the speaker. 15 watts sounds to be enough.
     
  6. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    There is nothing that says that the transceiver has to be terminated into either 4 or 16 Ohms, so why not use a higher impedance L-Pad so the L-Pad does not dissipate much power...
     
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