How do I change the roofing filter from 15kHz to 3kHz?
Cause/Symptom: How do I change the roofing filter from 15kHz to 3kHz?
Solution: The FT-991 roofing filter uses the 15 kHz filter on AM/FM/C4FM modes. All the other modes use the 3 KHz filter automatically. There is no manual selection possible.