Vertex Standard FT-1000MP - Manual (Page 17)

Page 15 O
PERATING
M
ANUAL
A
CCESSORY
I
NSTALLATION
D
IGITAL
M
ODEM
(TNC, W
EATHER
F
AX
,
ETC
.) I
NTERFACING
The MARK-V FT-1000MP Field offers special fea-
tures for digital modes, such as a built-in digitally-syn-
thesized AFSK generator for RTTY and AMTOR ter-
minal units, IF bandwidth optimization and automatic
display offsets, and an 18-ms transmit-to-receive turn-
around time.
Low-level Main Receiver audio output is provided
from the rear-panel RTTY and PKT jacks, and is unaf-
fected by front panel volume control settings. If you
prefer to use Sub Receiver audio for TNC input, switch
S3001 (located on the AF UNIT circuit board, inside
the transceiver, between the DVS-2 and PKT connec-
tors) can be moved from the MAIN to the SUB posi-
tion.
Audio level is 100 mV from both jacks. The RTTY
level is fixed; however, PKT audio level can be adjusted
by potentiometer VR3010. In many cases, it is easier
to perform level adjustments at the TNC.
D
IGITAL
M
ODES WITH A
TNC
OR
C
OMPUTER
S
OUND
C
ARD
(PSK-31)
The explosion of new digital modes of amateur com-
munication means that you will want to make connec-
tions to your TNC and/or computer as “standardized”
as possible. Generally, this will mean that you will want
to connect your transceiver in an “AFSK” environment.
On the MARK-V FT-1000MP
Field, the PACKET jack
is the “AFSK” connection port, while the RTTY jack is
an “FSK” connection port. In the AFSK mode, the TNC
or computer generates the data signal as a set of au-
dio tones, while the FSK mode uses a closure to ground
(in the TNC or terminal unit) to cause the transceiver
to generate the “mark” and “space” tones.
P ACKET T ONE I NFORMATION
TNC Tone Pair
1070/1270 Hz
1600/1800 Hz
2025/2225 Hz ø
2110/2310 Hz
Tone Center Frequency
1170 Hz
1700 Hz
2125 Hz ø
2210 Hz
ø indicates default setting (used by normal convention)