Wavecom W61PC V7.5.0 - Manual (Page 176)

166  Transmission Modes WAVECOM Decoder W61PC/LAN Manual V7.5
 Net Test
The data in the frames is coded with Hamming method.
To decode the mode, choose the correct Polarity, put the Doppler Tone cursor in the FFT tuning window to
the Doppler tone. Small frequency error (+/- 30 Hz) and Doppler shift will be corrected automatically and
displayed in the Freq Err/Doppler Shift field. The data will be displayed in the main text window. Because
the mode transmits link information, the data is displayed in a 30-bit group hex.
The frame format is displayed together with the baudrate in the Format field. Confidence shows the de-
coding quality: a value over 95 means the FEC has probably corrected all bit errors, the data decoded is
mostly reliable.
MD-674 ASYNC
MD-674 is an asynchronous FSK system and is based on ASCII. No error detection or error correction is
implemented.
Parameter Value
Frequency range HF
Operation modes Broadcast
Modulation FSK
Center frequency 1275 Hz
Shift 85 Hz
Symbol rate 50, 75, 100 and 150 Bd
Modulation FSK
Receiver settings DATA, CW, LSB or USB
Input format(s) AF, IF
Additional Info Async FSK only
For MD-674 mode standard baud rates from 50 to 150 Bd are available. Non-standard baud rates may be
selected using the Baudrate menu item.
From “Options | Alphabet...” ITA5 and ITA2 are available as output formats.
MD-674 is also known as Wireline FSK.
METEOSAT
The METEOSAT software has been specifically tailored to the transmissions of meteorological satellites
parked in geo-stationary orbit at 0.2 degrees East and transmitting on 1691.0 MHz. Transmissions are al-
ways at 240 rpm using an IOC of 288. In contrast to short-wave stations which use frequency modulation,
satellite weather images are transmitted using amplitude modulation. For this purpose the decoder is fit-
ted with a DSP AM demodulator with an integrated software FIR low-pass filter.
Parameter Value
Frequency range VHF/UHF
Operation modes Broadcast
Modulation FM, SUB AM
Speed 240 RPM
Receiver settings FM BW = 40 kHz
Input format(s) AF
Additional Info IOC 288