Audio Peak Filter - Yaesu FT-991A Operating Manual

Tools for Comfortable and Effective Reception
1. Press the F ( MLIST ) button to reveal the functions
list on the TFT LCD display.
2. Touch [ APF ] on the LCD. The APF function will be
set to "ON".
APF indicator
APF level indicator
3. Rotate the MULTI knob to set the sound volume to a
comfortable level.
Advice:
 The APF bandwidth can be selected from NAR-
ROW/MEDIUM/WIDE via the Menu item "111
APF WIDTH".
4. To cancel the APF action, touch [ APF ] on the LCD.
The "OFF" will appear in the display, confirming that
the APF system is no longer in operation.
Advice:
The APF may only be activated while the transceiver is
in CW mode.
Page 58

Audio Peak Filter

F ( M-LIST ) Button
MULTI Knob
FT- 991 Operating Manual