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I have a Baofeng UV-82HP that I want to use to TX and RX to a TeamSpeak Server. For this I'm going to use a dedicated computer, for both the client and server that has a sound card (ASUS Xonar Essence STX) that is not used by the OS or any other applications (so, there will be no spurious transmissions.)

I want to take the computer audio, and put that through the radio's accessory Microphone Port. That's a simple 3.5mm TRRS from the Radio's MIC port into the Line-In of the Sound Card.

I want to take the audio from the radio via the radio's accessory Speaker Port, and put that into the microphone for the sound card. From the Speaker Port I'm using a 2.5mm TRRS to 3.5mm TRRS adapter, then 3.5mm TRRS to the Line-In for the Sound Card.

The problem is when I complete the connection from the radio's accessory Speaker Port to the Sound Card's Line-In, it causes the radio to transmit. This happens even with the radios's accessory Microphone Port unplugged. It does not happen when the 2.5mm TRRS to 3.5mm TRRS adapter by it's self on the Speaker Port.

schematic

simulate this circuit – Schematic created using CircuitLab

The 2 Pin Kenwood uses a TRS style for both Speaker and Mic, should I use a TS for the Speaker to bypass the PTT functionality of the circuit?

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  • $\begingroup$ Did you ever solve this issue? I want to connect the input/output sound of the radio to a Bluetooth receiver, so very similar to you. Any hint appreciated. $\endgroup$
    – user48678
    Aug 31, 2020 at 7:17

1 Answer 1

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I have had this problem before. The circuits need to be isolated from each other. Either install capacitors in series with the audio or an isolation transformer (better option). An isolation transformer might also keep RF out of the audio signals.

For instance, where you have the 10uf capacitor, place another one between the other wire of the audio jack and the PTT switch.

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  • $\begingroup$ The circuit diagram is the stock Kenwood 2-Pin design for their audio accessories used in my post as a reference. I'm using 2 TRRS from my radio into my sound card. I want to know if the TRRS is the reason why my radio is keying up when ever I plugin it into my sound card, and if I should be using a TRS or TS connector instead, or even if that would help. $\endgroup$
    – Mark Tomlin
    Aug 31, 2015 at 4:17

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