For less than $15, the TS-9900 is replaceable. If you've spent more than an hour troubleshooting, buy a newer USB sound card based on the Realtek ALC4042 chip – it has native Windows 11 drivers and better noise isolation.
Check amateur radio forums (e.g., , RadioReference , eham.net ) or Kinamax TS-9900 user groups. Someone may have archived the original driver CD contents. kinamax ts-9900 driver 43
There is no "official" Kinamax TS-9900 Driver 43 from Kinamax. Instead, the TS-9900 uses a C-Media chipset . The most compatible driver for Windows 10 and 11 is the C-Media CM6206 (or CM108) driver version 8.0.x or 10.0.x , not "43". For less than $15, the TS-9900 is replaceable