I've helped a friend with getting a computer to record (via Audacity) output from a UV-5R+ before. I don't know if this would apply to whatever model radio you have.
Basically I followed the below image when attempting to run a line from the radio to the computer.
Based on that information, I had him get a 2.5mm to 3.5mm male to female stereo adapter (I recommended a mono adapter, but he got a stereo anyways) as well as a 3.5mm male to male cable. he basically plugged the 2.5mm side into the radio and then ran the 3.5mm cable from the adapter to the line in port on the computer and verified the correct audio levels desired using Audacity.
Some of the problems that he noted was getting the correct 2.5mm adapter. He grabbed a generic 2.5mm to 3.5mm off the shelf somewhere and noted that the base of the plug was too wide and didn't fit the port correctly (
something like this for example). Because of that, he shaved the base of the plug to allow it to fit into the 2.5mm port. He noted that getting a smaller 2.5mm adapter would be a lot better and something like an L shaped 2.5mm adapter might work best.
One of the problems he's run into with his shaved down 2.5mm plug is that he sometimes gets weird clicking noise, which I think is related to the radio attempting to establish some type of serial communications over the port due to using a stereo plug. He believes it might just be related to his attempt at fixing the plug allowing the plug to not seat correctly as the issue can be solved by moving the cable in different directions to make it stop. I'm still recommending that anyone who tries this get some type of mono to mono or mono to stereo adapter to avoid the TX Data. You can also consider just getting a 2.5mm to 3.5mm male to male cable in order to avoid purchasing an adapter and cable separately.
Hope that this was able to help!
