Wavecom W40PC, Руководство пользователя

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WAVECOM Decoders v6.15 W40PC, W41PC, W51PC General Operating Procedure
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Shift 115-170-115 Hz, center frequency 1700 Hz
In Twinplex mode four frequencies are keyed to increase the data transfer rate. These
frequencies may be asymmetrically grouped (e.g. 115-170-515 Hz).
In the Twinplex menu an option gives the operator a choice of six pre-selected shifts in the
dialog box "MFSK Shift".
The tuning of Twinplex transmissions must always be done in such a way that the two inner
frequencies are symmetrical relative to the tuning indicator center.
Tuning a CW-Morse Signal
Automatic pre-selection CW-MORSE demodulator
Bandwidth 200 Hz, center frequency 800 Hz
The transmission of Morse is often done by simply keying the carrier on and off. This
modulation is output by the receiver as a tone.
With no signal (tone) present the bar graph will remain turned off, whereas when a signal is
present one bar graph element will turn on at a position determined by the value of the beat
frequency relative to the selected center frequency.
The bandwidth of the CW demodulator may be adjusted between 50 and 1200 Hz. As a
standard adjustment a bandwidth of approximately 400-500 Hz is recommended. In case of
unstable transmission the bandwidth must be increased up to 1200 Hz. The automatically
adjusted FIR filter provides an optimized SNR (signal-to-Noise Ratio).
In addition to the bandwidth the center frequency may be adjusted from 500 Hz to 3500 Hz,
the center frequencies 800 Hz and 1000 Hz being standard.
Tuning a WEATHER-FAX Signal
Tuning with DSP demodulator
Shift 300 Hz, center frequency 1900 Hz
Weather and press facsimile signals transmitted in the HF bands are frequency modulated.
Satellite transmissions from e.g. METEOSAT are amplitude modulated.
In all modes the tuning of the FM or AM signal is done symmetrically around the center of the
bar graph. Weather chart signals containing no gray levels are characterized by white level
information being dominant, and as a result of this one or two elements of the left side of the
bar graph will be more intensively lit.
Tuning a MFSK Signal
Selecting "FSK Analysis"
Pre-selection center frequency 1700 Hz
MFSK signals like PICCOLO or COQUELET employ a varying number of tones. Therefore
tuning is most easily done using the "FSK Analysis" software. The downmost field graphically
displays the various tones which have been sampled over a certain time interval. In this case
the signal shown is a PICCOLO-MK6 transmission. By tuning the receiver or changing the