User Manual

2) External Source
When modulation source is external, carrier waveform will be modulated by an external
waveform. PM phase deviation is controlled by ±5V signal level of external modulation input
terminal on rear panel. For example, if phase deviation value in parameter list has been
set to 180˚, +5V of external modulation signal is equivalent to 180˚ phase shift. Lower
external signal produce smaller deviation.
Modulation wave Frequency Setting
When modulation source is internal, frequency of modulation wave can be modulated.
After enabling PM function, the default of modulation wave frequency is 100Hz. If need to
change, press Param → ModFreq in turn, and the modulation frequency range is 2mHz
to 1MHz. When modulation source is external, carrier waveform will be modulated by an
external waveform. The range of modulation signal input from external is 0Hz to 20Hz.
Phase Deviation Setting
Phase deviation indicates the change between the phases of PM modulated waveform and
the phase of carrier wave phase. Settable range of PM phase deviation is from 0˚ to 360˚,
and the default value is 180˚. If need to change, press Param → Phase Dev in turn.
Comprehensive Example
Firstly, make the instrument work in phase modulation (PM) mode, then set a sine wave
with 200Hz from the internal of the instrument as a modulation signal and a square with
frequency of 900Hz and amplitude of 100mVpp as a carrier wave signal. Finally, set the
phase deviation to 200˚. Specific steps are seen as following:
Enable Phase Modulation (PM) Function
Press Menu → Mod → Type → PM in turn to start the PM function.
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