Справочник Пользователя для InterAct Accessories 4040A

 

 

 

4. Connect a suitable modulation signal to the VCG/MOD 

INPUT jack on the front panel. 

5. Adjust the amplitude and frequency of the external 

signal as required. Typically, a signal less than 10V p-
p will provide 10% modulation of the carrier. 

The  TTL/CMOS output jack provides a fast rise time 

square wave output. Either a fixed TTL or a variable CMOS 
output level is available. The output is positive with respect 
to ground and can be used as an external sync pulse for 
oscilloscopes or as a variable frequency signal source for 
exercising logic circuits. Because of the fast rise time of this 
output, cable length should be minimized to limit ringing and 
overshoot. 

 

1. Select the desired frequency range and adjust the 

frequency controls as required. The OUTPUT LEVEL 
and  DC OFFSET controls have no effect on the signal 
at the TTL/CMOS jack. 

2. When the CMOS LEVEL switch (3) is released, a TTL 

signal is output at the TTL/CMOS jack. Select a CMOS 
signal by engaging the CMOS LEVEL switch and adjust 
the level of the signal by rotating the CMOS LEVEL 
control (8). 

 

VOLTAGE CONTROLLED FREQUENCY OPERATION 
The Model 4040A can be operated as a voltage-controlled 
generator by using an external control voltage applied to the 
VCG/MOD INPUT jack (12). The externally applied voltage

 

 

will vary the frequency which is pre-selected by the range 

switches and the frequency controls. Applying 
approximately +l0 V with the COARSE control at full 
clockwise decreases the output frequency by about 100 
times (a 100:1 ratio). 
 

1. Select the desired frequency range and waveform. 
2. Set the starting frequency with the COARSE control. 

Apply a positive DC voltage to the VCG/MOD INPUT 
jack (l2) to decrease the frequency. A voltage from 0 to 
+10 V will cause the frequency to decrease by a factor 
of 100 if the COARSE frequency control is set at 
maximum CW rotation. For example, if the starting 
frequency is 100 kHz, applying +10 V will change the 
output frequency to 1 kHz. 

3. To operate the function generator as a sweep 

generator, apply a positive-going ramp signal to the 
VCG/MOD input jack. As the ramp voltage increases, 
the frequency decreases. The rate of sweep can be 
adjusted by varying the frequency of the ramp signal. 

4. Specific frequencies can be selected by applying a 

fixed dc voltage to the VCG/MOD INPUT jack or the 
frequencies can be stepped by applying a stepped dc 
voltage. 

5. Do not apply more than ±15 volts (dc or dc + ac peak) 

to the VCG/MOD INPUT jack. Inputs of more than 15 
volts will not cause any further shift in the frequency 
and could cause damage to the generator. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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