B&K Precision 4052-4055 - Manual - Manual (Page 14)

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Before connecting to an AC outlet or external power source, be sure that the power switch is
in the OFF position and verify that the AC power cord, including the extension line, is
compatible with the rated voltage/current and that there is sufficient circuit capacity for the
power supply. Once verified, connect the cable firmly.
WARNING:
The included AC power cord is safety certified for this
instrument operating in rated range. To change a
cable or add an extension cable, be sure that it can
meet the required power ratings for this instrument.
Any misuse with wrong or unsafe cables will void the
warranty.
2.2 Output Connections
The waveform generator output circuits operate as a 50 Ω voltage source working into a 50
Ω load. At higher frequencies, a non-terminated or improperly terminated output may cause
aberrations on the output waveform. In addition, loads with an impedance less than 50 Ω
will reduce the waveform amplitude, while loads with an impedance greater than 50 Ω will
increase waveform amplitude.
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.