Apf Function; Cw Reverse Mode; Rtty Reverse Mode; Cw Pitch Control - Icom IC-756 Instruction Manual

4
RECEIVE AND TRANSMIT

APF function

The APF (Audio Peak Filter) changes the receive fre-
quency response by boosting a particular frequency
for better copying of desired CW signals. The peak
frequency can be adjusted with [APF] from 300 to 900
Hz manually. The boost frequency width can be se-
lected from 80, 160 or 320 Hz.
q Push [CW] to select CW mode.
w Push the [APF] switch to turn the audio peak filter
ON.
- The [APF] switch lights.
- " ," etc. appears in the LCD.
e Rotate the [APF] control to adjust the center fre-
quency of the peak frequency.
r Push [APF] for 2 sec. to select the boost frequency
width of the audio peak filter between 80, 160 and
320 Hz.
- " ," "
quency width.
t Push the [APF] switch momentarily to cancel the
audio peak filter.

CW reverse mode

CW-R (CW Reverse) mode receives CW signals with
a reverse side CW carrier point like that of LSB and
USB modes.
Use when interfering signals are near a desired signal
and you want to change the interference tone.
• Push [CW] for 2 sec. once or twice to select CW or
CW-R mode.
- Check the interfering tone.

RTTY reverse mode

Received characters are occasionally garbled when
the receive signal is reversed between MARK and
SPACE. This reversal can be caused by incorrect
TNC connections, settings, commands, etc.

CW pitch control

The received CW audio pitch and monitored CW
audio can be adjusted to suit your preferences (300
to 900 Hz) without changing the operating frequency.
27
" or " " indicate the fre-
APF indicator
14.100.00
• Receive audio tone response
1/3 octave
BFO
Push for 2 sec.
CW
Desired signal Interference
(600 Hz) (800 Hz)
CW mode (USB side)
To receive a reversed RTTY signal correctly, select
RTTY-R (RTTY Reverse) mode.
• Push [RTTY] for 2 sec. once or twice to select RTTY
or RTTY-R mode.
- Check the receive signal.
The received CW audio pitch can be adjusted in 3 Hz
steps.
[APF] switch
[APF]
control
1/2 octave
BFO
Desired signal Interference
(600 Hz) (400 Hz)
CW-R mode (LSB side)