Operating Rtty (Fsk); Ddisplaying The Rtty Decode Screen; Drtty Decoding; Dtwin Peak Filter (Tpf) - Icom IC-705 Advanced Manual

2. ADVANCED OPERATIONS

Operating RTTY (FSK)

The IC-705 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.
DDisplaying the RTTY DECODE
screen
With the built-in demodulator and decoder,
received RTTY chatacters are displayed on the
RTTY DECODE screen.
» DECODE
RTTY DECODE screen
Decoded or transmitting characters
Key
< 1 >
Selects the Function menus.
< 2 >
Turns the Hold function ON or OFF.
HOLD • is displayed, and the RTTY
HOLD
DECODE screen stops.
Clears the displayed characters.
• While the Hold function is ON, this clears
CLR
the characters and cancels the Hold
function.
Opens the RTTY MEMORY screen.
TX MEM
• Sending the RTTY MEMORY RT1 ~ RT8.
Displays the RTTY DECODE LOG screen.
LOG • You can start or stop logging, and select
the file type and the time stamp.
Displays the RTTY DECODE LOG VIEW
LOG VIEW screen.
• You can check the saved RTTY log files.
Opens the THRESHOLD screen.
ADJ
• You can adjust the threshold level.
Selects the Expanded or Normal
Touch
screen.
EXPD/SET
Touch for
Displays the SCOPE SET screen.
1 second
FFT Scope zone
Tuning indicator
Waterfall zone
Action

DRTTY decoding

Rotate
LInformation
• 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.
RTTY mode Normal
170 Hz 2125 Hz
Space Mark
( Displayed
frequency)
TIP: If you cannot receive, change the following
settings.
» SET > Function > RTTY Mark Frequency
» SET > Function > RTTY Shift Width

DTwin 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
2. Touch [TPF].
LTouching [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.
2-7
to tune a signal.
RTTY-R mode
2125 Hz 170 Hz
Space
BFO BFO
to open the Multi-function menu.
Mark
( Displayed
frequency)