Making this into a phone bug?

Discussion in 'Wireless & RF Design' started by Mathematics!, Nov 23, 2009.

  1. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    Ok so I built this simple FM transmitter awhile ago.

    Here is it's schematic
    http://www.reconnsworld.com/transmit/fm_trasm.gif

    I am wondering can I replace the electric mic with the input from a telephone green/red wires. I know that the voltage from these wires are around 50 vdc and the current is pretty low. What would I need to get the phone voltage/current in the green and red wires of the phone down to an reasonable level so I can take out the mic and in place put in the input from the phone wires.

    Would an audio transformer 1K to 8 ohm work or something because I have that. I want to keep this simple this shouldn't take alot of circuitary to replace the mic with the input of the phone.
    Thanks for any help.
    I don't want to create a totally new FM transmitter just want the ability to use the input voice signal of a phone instead of the mic in my transmitter to modulate with.

    So don't give me knew schematics for totally different FM transmitters or stuff.

    Also I know I would have to take account of the 90vac 20hz ring so as to not damage the transmitter when this occurs.

    Thanks for any help
     
  2. loosewire

    AAC Fanatic!

    Apr 25, 2008
    1,584
    435
    The roof,the washer and phone you may tilt the computer to,all In
    fun.If you can't take a joke. (Blast Me)
     
  3. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    Funny :)

    Ya, I like this stuff , what did tesla say a man has 2 reasons for doing anything the right reason and his real reason.

    But seriously , what would you have to do to convert the telephone line voltage/current into the equivalent mic level input in the transmitter circuit? I don't think I can directly hook the green and red wires into where the mic was. (think this high voltage would destroy the circuit )

    What would I have to convert could I use an audio transformer or something?

    Thanks
     
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