18
2. ADVANCED OPERATIONS
Operating RTTY (FSK) (Continued)
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.
In the RTTY mode, push
APF/TPF
.
• The TPF function is turned ON, and the indicator on the
key lights.
L
Pushing
APF/TPF
turns the Twin Peak Filter function ON
or OFF.
NOTE
: When you are using the Twin Peak Filter, the
received audio output may increase. This is not a
malfunction.
APF/TPF
D
RTTY decoding
Rotate
MAIN DIAL
to tune a signal.
Information
L
• 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 received signal strength,
when a signal is received.
• If you are receiving an RTTY signal but cannot decode
correctly, try in the RTTY-R (reverse) mode.
BFO
BFO
170 Hz
2125 Hz
170 Hz
2125 Hz
RTTY mode Normal
RTTY-R mode
Space
Mark
Space
Mark
TIP
: If you cannot receive, change the settings for
“RTTY Mark Frequency” and “RTTY Shift Width.”
MENU
» SET > Function >
RTTY Mark Frequency
MENU
» SET > Function >
RTTY Shift Width
D
Displaying the RTTY DECODE screen
With the built-in demodulator and decoder, received
RTTY signals are displayed on the RTTY DECODE
screen.
L
The decode screen for the PSK mode differs
slightly from that of the RTTY mode.
MENU
»
DECODE
RTTY DECODE screen
Decoded characters
Tuning indicator
Transmitting
Waterfall display
RTTY memory title
FFT scope
Selected band (MAIN)
Transmitting contents
(Example: RT1)
NOTE:
“
” appears next to the transmitting
status indicator on the RTTY DECODE screen while
buffering. If this appears, stop typing for a while and
try transmitting again.
( Displayed
frequency)
( Displayed
frequency)