This is long, but it combines multiple recommendations from the KX3 and Elecraft mailing lists into a single procedure.
First, update to the latest KX3 firmware. There was a new compression algorithm in 1.50 and fixes in 1.61 and 2.30.
Then, get your KX3 manual. If you can’t find a paper copy, download the latest KX3 Owner’s Manual. You will be looking up a few menu settings.
The audio adjustments are done in separate steps:
- Transmit audio equalization (TX EQ).
- Microphone bias config.
- Microphone gain.
- Compression level.