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OPERATING INSTRUCTIONS 
 
 
 
 
 
                                                 
 
 
13
 
 
 
 
 
4.  When the 2 Hz range is selected, the gate time is 10 seconds and 
the display is updated once every 10 seconds. The result of a 
frequency change will not be displayed until 10 seconds later. 
Adjust the frequency in progressively smaller steps, waiting for 
the display to update until the desired frequency is obtained. 
5.  When outputting square waves or when using the TTL output, 
terminate the cable into 50Ω to minimize ringing. Also, keep 
cables as short as possible. 
6.  Remember that the output signal swing of the generator is 
limited to ±10 volts open circuited or ±5 volts into 50Ω, and 
applies to the combined peak-to-peak signal and DC offset. 
Clipping occurs slightly above these levels. Fig. 3 illustrates the 
various operating conditions encountered when using the DC 
offset. If the desired output signal is large or if a large DC offset 
is required, an oscilloscope should be used to make sure that the 
desired signal is obtained without undesirable clipping. 
DUTY CYCLE CONTROL 
 
The  DUTY CYCLE control can be used to alter the symmetry of 
the output waveform, to produce waveshapes such as those shown in 
Fig. 4. For a square wave, symmetry variation amounts to changing 
the duty cycle (ratio of "high" to "low" time), effectively converting 
the instrument into a pulse generator. For a triangle wave, the result is 
a ramp, and with a sine wave, a distorted waveshape called a slewed 
sine is produced. The Model 4040 provides for symmetry variation 
from 15% to 85%. 
 
1.  Select the waveform desired either SINE, SQUARE or 
TRIANGLE. 
Figure 4. Effects of Symmetry Variation. 
2. 
Engage the DUTY CYCLE switch (2) and adjust 
the DUTY CYCLE control (7) for the desired 
waveshape. Clockwise rotation from center results 
in an increase in square wave duty cycle, and 
changes the sine and triangle waves as shown in the 
top waveform of each pair of Fig. 4. Counter-
clockwise rotation results in the bottom waveform 
in each pair.