Icom IC-2AT Mic Connector or Bafoeng UV-5R Mic Connector?

Discussion in 'Ham Radio Discussions' started by KC1NFJ, Sep 17, 2021.

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  1. KC1NFJ

    KC1NFJ Ham Member QRZ Page

    Hello,

    I am working to create a fox hunt transmitter using my Arduino and one of my HTs. I wanted to use my Icom IC-2At instead of my Baofeng UV-5R since it is lower power. However, the Baofeng connector cannot connect to the IC-2AT because the antenna is in the way. I also realized that the Kenwood connectors differ; The Icom's has two sleeves on each pin and the Baofeng's has three sleeves on each pin.
    What pins on the Baofeng correspond to the Icom's? I am not sure if the Baofeng's connector would even work if it could fit into the IC-2AT. My plan is to buy a 2.5mm to 3.5mm audio cable and cut it in half.
    How would the Icom's connector attach to the Arduino instead of the Baofeng's?
    [​IMG]
     
  2. KC1NFJ

    KC1NFJ Ham Member QRZ Page

    Here is a photo of the two mics and connectors I am referring to. A278FC42-A352-4402-8092-4F120ADE71CF.jpeg
     
  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    The Baofeng mic requires power.
     
  4. K7JEM

    K7JEM Ham Member QRZ Page

    On the Icom, the larger diameter plug is for the speaker only. Sleeve is ground, tip is "hot" side of speaker. The smaller diameter plug is for the electret microphone. The sleeve is ground and the tip goes to approx 5v source inside the radio, through a resistor. The external mic element has an approx 20K resistor across it. When it is connected to that "tip", the radio keys up, since it senses the current draw on that mic line. IOW, there is no separate PTT, you just have a switch inline to attach mic, and the current draw sensor in the radio will turn on the TX.

    You can feed audio into the mic input through a 1uF or so capacitor, and key the radio by switching a 10-22K resistor to ground.
     
  5. K7JEM

    K7JEM Ham Member QRZ Page

    Something like this: Also remember that the spacing between the two pins may be different between the Icom and the Baofeng
    NOTE: On review, the capacitor + symbol should be on the side towards the Icom, NOT on the side towards the board. The radio will have close to 5v on that mic connector, so the plus side of capacitor goes to it.

    ptt.jpg
     
    Last edited: Sep 18, 2021
  6. K7JEM

    K7JEM Ham Member QRZ Page

    Also, if you want to get rid of the relay board, you can substitute in a transistor, like a 2N3904 or similar:

    ptt2.jpg
     
    Last edited: Sep 18, 2021
    KC1NFJ, KA4DPO and KA9JLM like this.
  7. KC1NFJ

    KC1NFJ Ham Member QRZ Page

    Thank you very much! That cleared up everything I was confused about!
     

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