34
Interference Rejection
FT-891 Advance Manual
Digital NOTCH Filter (DNF) Operation
The Digital NOTCH Filter (DNF) is an effective beat-canceling filter that can null out
multiple interfering beat notes inside the receiver passband. Because this is an Automatic
Notch feature, there is no adjustment associated with the filter.
Note:
If a very strong interfering carrier is encountered, we recommend using the IF
NOTCH filter first, because it is the most effective notching tool in the receiver
section.
1. Press the [
F
] key repeatedly, to find the
“FUNCTION-2” list screen.
2. Rotate the
MULTI
function knob to select
“DNF”.
3. Press the
MULTI
function knob.
The Digital Notch Filter will turn on.
4. Press and hold the [
F
] key for one second
to exit the “FUNCTION-2” list screen and re-
sume normal operation.
r
To set the DNF to “OFF”:
1. Press the [
F
] key repeatedly, to find the “FUNCTION-2” list screen.
2. Rotate the
MULTI
function knob to select “DNF”, then press the
MULTI
function knob.
3. Press and hold the [
F
] key for one second to exit the “FUNCTION-2” list screen
and resume normal operation.
r
DNF function may be assigned to the [A], [B] or [C] key. Refer to “Changing the
function assigned to the [A]/[B]/[C] keys” in the FT-891 Operating Manual.
