In plain language: Interface a computer to an HF radio by providing the functions the application actually needs: receive audio, transmit audio, PTT or VOX, optional CAT control, and sometimes a dedicated data or USB connection.
Why the station behaves this way
Audio ground loops, USB noise, incorrect levels, duplicate control paths, and radio menu settings can create faults that look like software problems.
A common wrong turn
Connecting every available cable at once makes diagnosis harder and may allow both CAT and VOX to key the radio unexpectedly.
What to do at the radio
Read the radio and interface manuals, start with one signal path, select the correct computer devices, set levels at low power, add CAT control deliberately, apply needed isolation or choking, and test transmit inhibit.
Operating boundary
Use current equipment instructions, legal operating limits, the exact signal path, and observed conditions. A connector, software label, transformer ratio, or forecast value does not prove complete-system performance.
