Computer headset or other 1/8" speaker/mic mods

I’ve seen multiple mentions of modding a standard 1/8" computer speaker/mic headset for SSB operation. But I haven’t been able to find a decent schematic. I have a headset lying around with a busted jack, which seams like the perfect unit to start with for some rewiring. Can anyone point me in the right direction for instructions on how to do this with an FT-817 or a KX2 (the two radios I’m considering)?

I have decent soldering skills, but haven’t tried a project like this before. Would love to get some practice and save the cost of a mic!

To see whatyou rig needs to see, try this file for info first:

Of course the first thing you could find is that your computer headset uses a very small capacitor or electret microphone insert, which not only might not be a very good quality audio but may also need a bias (aka phantom) voltage on it to make it work at all.

If your rig expects a dynamic microphone, the PC microphone may not work at all.

73 Ed.

Is this what you are looking for?

These are both great! Not seeing anything for the KX2, but I’m guessing it’s too new for that. Looks like it uses the same connector as the KX3, but different from the K3S.

There are quite a few computer headsets that work with the KX2 and KX3. A lot of contesters like the Yamaha CM500 ($45) and the Koss SB45 ($25). Both have electret microphones that have far more fidelity than needed for voice communications. They are plug-and-play with the KX2 and KX3.

You can get better transmit audio by separating the logic bias (mic buttons) from the mic bias. I wrote up how to do that with a simple stero splitter. It also gives you a PTT jack.

Next step is setting mic level, TX EQ, and compression. I walk through that procedure for the KX3 here.



@K6WRU that’s incredibly helpful! So the KX3/KX2 just have two 1/8" jacks for speaker and mic? Way simpler than I thought it’d be. And your mod to enable a manual PTT switch instead of using VOX (which I assume is the only other option) looks terrific. Thank you for posting these – I’ll be referring to them for sure if I end up with a KX2!

That is correct. One jack for phones, one for mic. If you plug the mic in without the splitter, it will short the “mic button” contact and the rig will start transmitting. You can disable the mic buttons in the menus.

In the field, I use the MH3 hand mic and Apple ear buds.


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Personally I use something like this. For $25 its an easy buy.


Have a look at G8JNJ 's website in particular “Using PC boom headsets with Amateur Transceivers Yaesu FT-857 FT-897
Icom IC-7000”.(
This also works with the FT-817.

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