PeakTech 4105 Bedienungsanleitung Seite 106

5.7.5 Modulating Source
The waveform generator will accept an internal or external modulation source for Sum. Press
〖Source Int/Ext〗softkey. It's available to set modulating frequency and modulating waveform if
'Internal' source is selected. But if you select External source, the carrier waveform is modulated with
an external waveform. The frequency deviation is controlled by
the ±5 V signal level present on the rear-panel Modulation In connector.
5.8 Frequency -Shift Keying Modulation (FSK)
The FSK rate is the rate at which the output frequency "shifts" between the carrier frequency and the
hop frequency when you select the internal FSK source, and hop rate is depends on FSK rate. Press
【Modulate】key then select the FSK using the 〖Mod Type〗softkey. The FSK waveform is output
using the present settings.
5.8.1 Set Carrier
Firstly, set the shape, frequency, amplitude and offset of Carrier Waveform. You can select most
waveforms from above table to be carrier, but some waveforms are not available.
5.8.2 Hop Frequency
Press 〖Hop Freq〗 softkey and then set the desired value of hop frequency. FSK modulation is similar
to FM that modulating waveform is Square. And hop frequency is similar to frequency deviation. But
the difference is that, frequency deviation is the frequency of carrier wave plus or minus deviation
value, whose setting range is relational with the frequency of carrier wave, while hop frequency has
no relationship with it.
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