WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V9.1.0
Transmission Modes
225
If the
Auto
function is selected the software waits for the IOC identifier and synchronization sequence.
Both parameters are only transmitted at the start of an image and hence capture will only start when the
next image occurs. By selecting
PRESS-FAX
, the decoding starts immediately and the drum speed and
IOC can be programmed manually via the
Drum speed
and
IOC
items in the
Demodulator
menu. The
selected parameters are displayed in the decoder status bar.
The decoder allows a continuous and smooth alignment of the image as it is being received from
Op-
tions/Fine Speed
. By using the
Phase
item in the
Options
menu the image can be shifted into the cor-
rect position.
Flip Left-Right
and
Flip Top-Down
will reverse the image or turn it upside down.
To enhance the interpretation of gray-scale images, a false
color
option is available. Right-click on the
image to opens the
Zoom
menu, and select a color scheme from the bottom part. A checkmark is placed
to the left of the selection.
PSK-10
PSK-10 is a very narrow-band and reliable mode developed by F6CTE. The aim of this experimental slow
mode is to allow a chat-type communication between hams.
Parameter
Value
Frequency range
HF
Operation modes
Simplex
Modulation
DBPSK
Shift/Bandwidth
40 Hz
Symbol rate
10 Bd
Receiver settings
DATA, CW, LSB or USB
Input format(s)
AF, IF
Additional Info
10.148 MHz, 14.075 MHz
The baud rate is fixed at 10 Bd and is optimized to transfer the data rate, which an operator can input on
a keyboard by hand.
To separate the transferred characters, the sequence "011" is inserted between every character. Thus the
characters can be clearly separated, as long as no "011" sequence appears in the character itself. This was
taken into consideration when designing the alphabet.
To optimize the data throughput rate of the system, an alphabet with a variable character length is used.
For frequently used characters a symbol is used, which has a short word length (as is done with the Huff-
man compression). This alphabet is called Varicode and differs from the alphabet used in PSK-31.
PSK-31, PSK-63, PSK-125, PSK-250
PSK-31 is a very narrow-band and reliable mode. The good performance against disturbances is achieved
by the use of DPSK modulation. Two demodulators are available:
Parameter
Value
Frequency range
HF
Operation modes
Simplex
Modulation
DBPSK, DQPSK
Symbol rate
31.25, 62.5, 125 or 250 Bd
Receiver settings
DATA, CW, LSB or USB
Input format(s)
AF, IF
Additional Info
3.580 MHz, 7.035 MHz, 14.070 MHz
