How do I Convert Headset From 3.5mm to 2.5mm????

I have some super micro walkie talkies that I am trying to hook up a pair of iso tunes headset to. The problem is the headset is 3.5mm male jack and the walkie talkie is a 2.5mm female jack. I have tried 5 adaptors now and none of them work. Even when i file down the shoulder to make sure the poles align properly.

Now i have cut the wires on a 2.5mm male mono jack and cut off the 3.5mm iso tunes jack thinking i could just manually wire them together and it still wont work! I think i have tried every wire combination but I must be doing something wrong. The closest I got was everything worked except the push to talk button was always transmitting unless I pushed the button then it stopped. Like it was backwards. Can anyone help???

Sorry for the wide pictures. Re sizing wont work for me either.

There are a few things working against you here. You are attempting to wire a mono connector to a stereo device. The original connector for your headset was not in the images, but based what seems to be an inline mic on the device, I am guessing it was a 4-pole connector.

What you need is a stereo to mono adapter, but one that adapts a four pole 3.5mm connector to a two pole mono connector. A typical stereo to mono adapter won’t work.

It may be possible to wire it manually. The problem is, you need to know how the 2.5mm port is wired in the radio. Another issue is the 2.5mm adapter itself. A lot of two way radios use 2.5mm or similar size connectors, but they are often proprietary to the brand or manufacturer of the unit. Just because the connector is the correct diameter or physically fits in the hole, doesn’t mean it’s going to work. There are different lengths and styles of these connectors with different tip lengths, pinouts and poles. Without an internal schematic for the radio and its audio port, you are shooting in the dark.

Unless you’re doing this just for fun, I would have to ask, why? From the images, this seems like a fairly expensive earpiece to destroy for the sake of experimentation. There are a lot of headsets on the market that are specifically designed for two way radios, and many of them are very inexpensive. We carry a huge selection of earbuds and headsets. We may have one that works with your radio without any inconvenience or stress of modification at all.

Thanks for the reply. I have teams of guys that cut grass and we need to communicate. The problem is the noise. I cant hear or talk on a walkie talkie with the mower going. I know there is ear muffs with built in walkie talkies but they are ridiculously expensive and fill up with sweat and get caught on branches and pinch our glasses against our head. The ear buds with mic work awesome and the mic is so close to our mouth is comes through so clear. I have tried so many adaptors now. None of them work. I got to hard wire it. But like you said im shooting in the dark.

That’s why I don’t quite understand. When I say “headsets”, I’m not referring to an earmuff with a built-in radio, I’m referring to everything from stand-alone noise reduction headsets to single ear earpieces and everything in-between, including earbuds with in-line mics like the one in your photo.

Why try to graft a questionable connector onto an expensive set of earbuds that weren’t specifically designed for your radios when there are quite a few other earbuds out there that probably have the connector you need.

The closest I got was everything worked except the push to talk button was always transmitting unless I pushed the button then it stopped. Like it was backwards.

Which PTT button are you referring to? Is it on your earpiece or on the radio itself? If there isn’t one on your earpiece, it was likely designed for use with a mobile device, such as a cell phone, and not a radio, which would cause the issue you are describing. Keep in mind that cell phones are duplex devices, while two way radios (walkie talkies) are not. If your earbuds are made for cell phones, they are wired for being always on. Earbuds for radios with in-line microphones have a PTT button to activate the microphone when you speak.

If these earbuds are for your phone, for practical purposes, what you are attempting to do with your earbuds probably won’t work well, if at all. They simply weren’t designed for use with two way radios.

Where can i buy iso tunes with a 2.5mm mono jack? Where can I buy any noise isolating ear buds with a 2.5mm jack? There is no adaptor from 2.5mm to 3.5mm that works. I got a big pile of adaptors that i tried to get to work.

The PTT button makes sense. I guess I have to cut off the original walkie talkie headset ear bud and wire the isotunes ear buds on and use the original button.

This really is NOT rocket science. The headset has pretty standard tinsel cable which is a real pain to solder. The first thing to do is identify the two pairs in the 4 core cable. find an AA battery - grab one of the tinsel ends, scratch the enamel coating of with a sharp blade (it’s not really enamel any more - usually a polymer coating now, but it has to go!). Put one of the tinsel ends on the bottom of the battery, and one of the others on the top, with the headphones in your ears. One of the three will crackle - these two make a pair. the other two will be the other ear pair. Make a not of the colours.

Next - remove the cover from the 2.5mm jack plug - it’s a 3 circuit type. The sleeve is the common and one off the two others will be for the speaker, and the other for a microphone - which you don’t have. The radio detects the microphone impedance when it is connected and switches to transmit. The other circuit is the speaker. So take your pair of colours that crackled on the battery, and try sleeve to tip and see if you hear received audio. If not, then the connection will be sleeve and ring, no connection to tip.

Next issue will be soldering. Once you have scratched off the insulation just at the end, you need a VERY hot iron - 25W should do it. Apply the heat, press hard and apply solder, which should flow to where the insulation was removed. Do the same to the other three conductors. Next is to tin the plug terminals. If the plug has a hole on each tab, enlarge it so both tinned ends of each pair go through the hole, and then with a pair of pliers squash the hols to mechanically grab the tinned ends. Then you can apply the soldering iron and add some solder, before the **** plug melts. If you don’t fancy that - then with a meter, find the correct connection on the moulded end you have, and make the joints externally - A good trick is to slid onto the cable before you solder it, some sleeving. A tube - maybe even a sliced off bit of biro tube. once you’ve soldered, insulate with a thin bit off tape and test. If they work and the joint is good, then slide the tube over the joint, squeeze in some epoxy from both ends and then shove in the cable a bit further and leave the epoxy to set.

The only concern is that on some radios, the combined mic/spkr plug prevents the internal microphone being selected. Inserting the plug makes the radio believe the external one is to be used.

This isn’t a hard electronic job, but is very dependent on how well you can solder.

I would avoid even thinking about adaptors, because what you want isn’t really possible with standard adaptors - and 2.5mm adaptors are awful unreliable things that strain the 2.5mm socket badly.

Thanks for the reply. I agree with you for the adaptors. But i gave up on getting the ptt button and mic to work. Now i just cut off the original ear bud and soldered on the noise isolation ear bud. I found a great way to solder the wires. I leave the insulation on and twist the wires together and slowly run them through a blob of liquid solder. Connection comes out crystal clear and really strong if someone tugs on the cord.