Wavecom W61PC V7.5.0 - Manual (Page 85)

WAVECOM Decoder W61PC/LAN Manual V7.5 Analysis Tools  75
Zoom
Right-click with the mouse into the spectrum
or baudrate graph pane (upper panes) and se-
lect if you like to Zoom 2X or or to Zoom 4X. To adjust the frequency scale, move the cur-
sor into the range of the frequency scale. If
you see the “Hand”, press the left mouse but-
ton and move the frequency slider.
FSK Code Check
The purpose of the FSK Code Check is to automatically identify the mode of transmission, baud rate, fre-
quency shift and center frequency.
FSK Code Check HF
FSK code check is started in automatic mode by selecting the Analysis | Code Check button or from HF-
Modes | Analysis | FSK Code Check. This function has a high degree of accuracy when determining
baud rate, frequency shift and center frequency of HF FSK systems.
As an additional aid, FSK code check also offers an option to start the analysis manually after user entry of
baud rate, frequency shift and center frequency. To utilize this option the Auto button must be deselect-
ed. The software will then start data acquisition using the pre-selected parameters. If a pre-selected pa-
rameter has been changed data acquisition is atomatically restarted.
The selection of baud rate, frequency shift or center frequency is done by clicking on the status bar fields
or using the Demodulator menu.
If the FSK code check cannot identify a mode, the code check should be repeated. Data acquisition is con-
tinuously performed as a background task. Heavy fading or other disturbances during data acquisition
may prevent the identification of a mode.
You can also restart data acquisition by pressing the Resync button
The 1.5 stop elements used in many Baudot transmissions will often prevent the correct determination of
the signal baud rate, or the baud rate will be calculated as twice its actual value. Distorted stop elements
may also lead to completely erroneous baud rate calculations. To prevent this malfunction, measurements
of Baudot transmissions take place using the standard speeds of 45.45, 50, 75, 100, 150 and 180 Baud, in
addition to the measured baud rate.