Rtty (Radio Teletype) Operation; Setting Up For Rtty Operation; Basic Setup - Yaesu FT-450 Operation Manual

RTTY ( R
Most RTTY operation today is accomplished using a TNC or other computer-based system that utilizes AFSK
tones. For RTTY operation using a Terminal Unit (TU) or the "FSK" output from a TNC, please see the discus-
sion below. See also the illustration for details regarding connection to your TU.
Before commencing RTTY operation, please direct
your attention to the setup steps shown in the chart
to the right.
1. Press the [ MODE ] / [ MODE ] buttons several
times to indicate both the "
on the display. Engage the RTTY operation us-
ing "LSB" injection, which is generally used in the
Amateur service.
2. When you begin typing on your TU or computer
keyboard, the command to transmit should auto-
matically be sent to the transceiver, causing it to
enter the transmit mode.
N :
If you anticipate making data transmissions of longer
than a few minutes, we recommend that you reduce
the transmitter power to 1/2 ~ 1/3 of its normal maxi-
mum via Menu Item "RFPOWER".
Q P :
In the FT-450, "RTTY" is a mode defined as being an
"FSK" mode, whereby the closing and opening of a
keying line (to ground) causes the Mark/Space tones
to alternate. The RTTY mode is not an AFSK based
mode in this transceiver, and the AFSK output tones
from a TNC will not cause Mark/Space shifting to oc-
cur. Use the "Packet" mode for AFSK-based Baudot
and other data modes.
Page 72
T
ADIO ELETYPE
ANT
INPUT
DC 13.8V
22A
EXT
GND
SPKR
DATA TUNER LINEAR CAT
DATA JACK
DATA IN (Pin 1)
GND (Pin 2)
DATA PTT (Pin 3)
FSK IN (Pin 4)
DATA OUT (Pin 5)
)
SQL OUT( Pin 6
S U
ETTING P FOR
B
ASIC
" and " " icons
) O
FSK AF
OUT IN
TU
N.C.
GND
PTT
FSK OUT
AF IN
N.C.
RTTY O
PERATION
M I
RTY SFT ( RTTY SHIFT )
RTY TON ( RTTY TONE )
RTYRPOL ( RTTY RX POLARITY )
RTYTPOL ( RTTY TX POLARITY )
S
ETUP
A :
There is no adjustment of the FSK input level
(FSK IN of the DATA jack) on the rear panel;
please make any needed level adjustments at the
TU side.
The Mark/Space Shift utilized in most Amateur
RTTY operation is 170 Hz. Other shifts may be
configured, however, using Menu Item "RTY SFT".
The FT-450 is set up for "high tone" operation
(centered on 2125 Hz) by default, but you may
configure it for low tone (1275 Hz) operation us-
ing Menu Item "RTY TON".
You may find that you are unable to decode some
RTTY stations, even if they are of sufficient sig-
nal strength. If this is observed, there may be a
Mark/Space polarity problem between your sta-
tion and the other station. If so, try setting Menu
Item "RTYRPOL" to "REV" ("Reverse") to see if
that permits copy. A separate Menu Item permits
reversal of your transmitter's Mark/Space polar-
ity: "RTYTPOL."
FT-450 O
PERATION
PTT
A V
170 / 200 / 425 / 850 Hz
1275 / 2125 Hz
NOR / REV
NOR / REV
M