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Excessive distortion or aberrations caused by improper termination are less noticeable at lower
frequencies, especially with sine and triangle waveforms. To ensure waveform integrity, follow these
precautions:
1.
Use good quality 50 Ω coaxial cable and connectors.
2.
Make all connections tight and as short as possible.
3.
Use good quality attenuators if it is necessary to reduce waveform amplitudes applied to
sensitive circuits.
4.
Use termination or impedance-matching devices to avoid reflections.
5.
Ensure that attenuators and terminations have adequate power handling capabilities.
If there is a DC voltage across the output load, use a coupling capacitor in series with the load. The
time constant of the coupling capacitor and load must be long enough to maintain pulse flatness.
Impedance Matching
If the waveform generator is driving a high impedance, such as a 1 MΩ input impedance (paralleled by
a stated capacitance) of an oscilloscope vertical input, connect the transmission line to a 50 Ω
attenuator, a 50 Ω termination and to the oscilloscope input. The attenuator isolates the input
capacitance of the device and terminates the waveform generator properly.
2.4 Preliminary Check
The 4047B is intended for bench use. The instrument includes a front feet tilt mechanism for
optimum panel viewing angle. The instrument does not require special cooling when operated within
conventional temperature limits. It may be installed in a closed rack or test station if proper air flow
can assure removing about 15 W of power dissipation.
Complete the following steps to verify that the generator is ready for use.
1.
Verify AC Input Voltage
Verify and check to make sure proper AC voltages are available to power the instrument.
The AC voltage range must meet the acceptable specification as explained in 2.1 Input
Power and Fuse Requirements.
2.
Connect Power
Connect AC power cord to the AC receptacle in the rear panel and press the power switch
to the ON position to turn ON the instrument. The instrument will have a boot screen
while loading, after which the main screen will be displayed.
3.
Self Adjust
At power-on, the waveform generator performs a diagnostic self-test procedure to check
itself for errors. If it finds an error, an error code and text will appear in the display
window. Other error codes appear when you enter an invalid front-panel setting. For more
information on error codes, see the 3.7 Displaying Errors. When the waveform generator
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