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1
ADVANCED OPERATIONS
1-8
Operating RTTY (FSK)
The IC-905 has a built-in RTTY decoder and encoder�
Using contents set in the RTTY TX memory, you can
do basic RTTY operations without using an external
device or software�
D
Displaying the RTTY DECODE screen
With the built-in demodulator and decoder, received
RTTY characters are displayed on the RTTY
DECODE screen�
»
DECODE
RTTY DECODE screen
Key
Action
< 1 >
< 2 >
Selects the Function menus�
HOLD
Turns the Hold function ON or OFF�
•
HOLD
is displayed, and the RTTY
DECODE screen stops�
CLR
Clears the displayed characters�
• While the Hold function is ON, this clears
the characters and cancels the Hold
function�
TX MEM Opens the RTTY MEMORY screen�
• Sending the RTTY MEMORY RT1 ~ RT8�
LOG
Displays the RTTY DECODE LOG screen�
• You can start or stop logging, and select
the file type and the time stamp.
LOG VIEW
Displays the RTTY DECODE LOG VIEW
screen�
•
You can check the saved RTTY log files.
ADJ
Opens the THRESHOLD screen�
• You can adjust the threshold level�
EXPD/SET
Touch
Selects the Expanded or Normal
screen�
Touch for
1 second
Displays the RTTY DECODE SET
screen�
D
RTTY decoding
Rotate
to tune a signal�
L
Information
• Aim for a symmetrical wave form, and be sure the peak
points align with the mark (2125 Hz) and shift (170 Hz)
frequency lines in the FFT scope�
•
Tune to where both “◄” and “►” are displayed in the
tuning indicator�
• The S-meter displays the signal strength, when a signal is
received�
• If you are receiving an RTTY signal but cannot decode
correctly, try the RTTY-R (reverse) mode�
TIP:
If you cannot receive, change the following
settings�
» SET > Function >
RTTY Mark Frequency
» SET > Function >
RTTY Shift Width
D
Twin Peak Filter (TPF)
The Twin Peak Filter (TPF) changes the audio
frequency response by boosting the mark and space
frequencies for better reception of RTTY signals, or for
decoding the AF output signal on a PC�
1� Push
to open the Multi-function menu�
2� Touch [TPF]�
L
Touching [TPF] turns the Twin Peak Filter function
ON or OFF�
3� To close the Multi-function menu, push
�
NOTE:
When you are using the Twin Peak Filter, the
received audio output may increase� This is not a
malfunction�
Decoded or transmitting characters
Tuning indicator
FFT Scope zone
Waterfall zone
BFO
BFO
170 Hz
2125 Hz
170 Hz
2125 Hz
RTTY mode Normal
RTTY-R mode
Space
Mark
Space
Mark
( Displayed
frequency)
( Displayed
frequency)