Start here: FT8 is a tightly timed weak-signal digital mode designed for short structured exchanges in challenging conditions.
Why this changes a real station
Its 15-second sequence, narrow occupied bandwidth, synchronized clock, and automated decoding make it efficient—but not suitable for long free-text conversations or emergency messages.
What it looks like in practice
A station can decode far below the voice noise floor, yet excessive audio drive will still create wide interference across the shared FT8 segment.
What to do next
Synchronize the computer clock, disable processing, set clean low audio, choose an open offset, use minimum necessary power, and monitor duty-cycle limits.
Evidence boundary
Keep frequency, reference plane, antenna geometry, losses, measurement method, and safety conditions attached to the conclusion. A match, a DC check, or one field symptom does not prove efficiency or identify the complete RF path.
