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Problem with Headphones

We have purchased four Cobra MT600 radios and also purchased four 2.5mm jacks to allow us to use four Universal headsets. However when we plug them in they seem to transmit continously. To combat this we turned on the VOX, but on both settings we cannot transmit vocally.

Can you help?

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  • stbcrossroad Dec 19, 2008

    Is there anyway to use headphones with the Atlantis 250.



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Can you pls add a few more details:
1. are the 2.5mm jacks stereo (3 pins) or mono (2 pins):
2. is your universal headset monaural or stereo; and
3. originally, did the universal headset came with 2 separate plugs?

At most that I can give you is a general/generic idea. The external speaker/microphone (or in your case the universal headset) uses also the charge jack, chances are that it is a multi terminal/pin jack. Pls refer to the diagram below.

Problem with Headphones - 5be4da5.jpg

The reason it is in continuous transmit is because one of the mini speaker is wired to the PTT trigger or the pins are wired wrong;

This would also explain why no transmit audio either manual or via VOX.

Hope this be of some help/idea. Post back how things turned up or should you need additional information.

Good luck and kind regards.

Posted on Nov 03, 2007

  • Louie  Role
    Louie Role Feb 01, 2008


    Any developments with your headset/2-way radio project?



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