63
FT-857 Operating Manual
T
RANSMITTER
O
PERATION
D
IGITAL
M
ODE
O
PERATION
(
SSB-B
ASED
AFSK
)
The
FT-857
provides extensive capability for digital mode operation on the HF, VHF, and
UHF bands. The use of AFSK (Audio Frequency-Shifted Keying) configurations allows a
wide variety of different communication modes to be utilized. The Menu provides for spe-
cific digital mode selections, which include custom BFO offsets to optimize the receive and
transmit passbands for the mode selected.
Before beginning Digital operation, you need to define which Digital mode will be utilized.
To do this, use Menu #38 as follows (in this example, we will set up RTTY as the Digital
mode):
1. Press and hold in the [
FUNC
] key for one second to enter the Menu mode.
2. Rotate the
SELECT
knob to recall Menu Mode
No-001
[
EXT MENU
]
, then rotate the
DIAL
to change the setting to “
ON
” to enable the extended Menu Mode.
3. Rotate the
SELECT
knob to select Menu Mode
No-038
[
DIG MODE
]
.
4. Rotate the
DIAL
knob to select “
RTTY-L
” or “
RTTY-U
” (see discussion below).
5. Press and hold in the [
FUNC
] key for one second to save the new setting and exit.
Use this basic technique to set up any digital mode.
RTTY (Radio TeleType) Operation
The “RTTY” mode on the
FT-857
is available in either LSB-side or USB-side BFO injec-
tion. Long-standing Amateur practice calls for the use of LSB-side injection, but some ap-
plications require that you use USB-side injection.
1. Connect your TNC (Terminal Node Controller) or termi-
nal modem to the
FT-857
’s rear-panel
DATA
jack, per
the illustration. Be sure to use the “TX AUDIO” line, not
an “FSK” line, for the transmit data connection to the
FT-857
.
2. Press the [
MODE
(
t
)] or [
MODE
(
u
)] key, as needed,
to select the
DIG
mode (the “
DIG
” icon will appear on the
display). You should now be able to tune around the band,
and any RTTY signals heard should be capable of being
decoded.
3. If the optional
YF-122C
500 Hz filter or
YF-122CN
300 Hz filter has been installed, it may be used for RTTY
work. Recall Multi Function Row “n” [
CFIL,
– – –
,
– – –
],
then press the [
B
](
–
) or [
C
](
–
) key to engage the narrow
filter.
4. To set up the transmit side, be sure that the Meter is set to
P
T
T
D
A
T
A
I
N
G
N
D
AFSK
OUT
AF IN
PTT
DATA OUT