quick question on two cobra hand helds in regards to earpiece/headsets.

Fellas,

I have 2 different styles of walkies, one is a large Cobra MR HH425LI and the other is a CTX400, I’m trying to find low profile single ear piece and boom mike (either lapel or a hand mic, doesn’t matter)

my problems exist in that the larger cobra has a 3.5mm style plug with the threaded top. I’m guessing for a shoulder mounted speaker/mic combo. not what I’m looking for, I was told I couldn’t use an ordinary set on this particular radio because of wiring differences. doesn’t make sense to me that they wouldn’t run some sort of standardized plugs, but I also don’t want to spend a bunch of money only to find them not to work.

same problem sort of with the CTX400. it has a jack on the top that the instructions say is a headphone/mic/charge port. it is a 2.5mm plug that I have now tried 3 different 2.5mm style headsets on, and all do the same thing, they open the channel, and don’t close it. ptt button on the radio or on the boom mics have no effect. unplug it, and the channel closes. you can hear the open channel in the ear when it’s plugged in, but neither mic works. when the walkies are unplugged, they work great, flawlessly. all 4 radios I have had sitting on a shelf for some time brand new, not even scratched boxes, so I highly doubt there is something wrong with them, never dropped or wet.

any help or product recommendations would be highly appreciated.