I read about this over on the KX3 email reflector the other day, on connecting your KX3 to a headset like the Yamaha CM500’s which are what I use with the KX3. Initially I had been using this headset without the adapter pictured below and had good audio reports, but apparently you can get even cleaner transmit audio if you separate the bias voltage which is used to control the PTT & up/down buttons on the Elecraft MH3 microphone. Link to adapter here.
I’ve tried using just the hand mic in the field, the problem is I can never keep my mouth in front of the microphone because i’m constantly looking around checking my surroundings, especially when in a populated area. I’ve become quite accustomed to using a headset, even at the home QTH. I’ve been trying the microphone on boom thing for awhile now, and just can’t seem to get comfortable with it.
The 1/4″ to 1/8″ adapter is used for my PTT switches which all use 1/4″ connectors. The PTT switch will plug into the red (ring) connector, and the microphone will plug into the black (tip) connector. Kind of a bonus to be able to add a PTT switch and do away with pressing the ‘XMIT’ button! The CM500’s will run you around $59 right now, the price is pretty steady – but there have been reports that the Koss SB-45 headset works just as well. The headbands and material look a bit different & I particularly like the comfy CM500’s!
This headset will work well with iCOM radios, as well as any other type of radio that uses an Electret type microphone. You’ll just need an adapter that works with your particular radio. This may even work with the new Xiegu X5105 if you happen to be the owner of that new guy. If you are looking for a dynamic headset that won’t break the bank, check out the Koss SB-40’s. Be particularly careful when using the equalizer on this type of headset though – I find the element to be quite hot as it is, just like the MH3 hand mic, and requires little to no EQ at all to sound good on the air. Adjust ALC accordingly, I like to keep the KX3 around 3-4 bars on SSB to get good output.