BK Precision 4070A User Manual Rev.2.2
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Introduction
The Sweep mode continuously changes the frequency of a fixed amplitude sinusoid between a specified start
frequency and stop frequency. The user can set sweep time as well. The frequency may be stepped between the start
and stop frequency linearly. A sweep direction, up or down, could be specified.
The user could choose continuous or triggered type sweep. In the Continuous mode, the sweep is restarted once
the stop frequency reached. In the Triggered mode, the output waits at the start frequency until a trigger condition
happens. Triggers can come from a front panel key press, a rising edge on the EXT Trigger connector, or an ASCII
"T" on the terminal port. Once a trigger occurs, the output frequency is swept to the stop frequency and the sweep is
then reset to the start frequency. The unit then awaits another trigger condition. For downward sweeps, the output
frequency begins at the stop frequency and ends at the start frequency.
Sweep Mode Parameters
The Sweep mode has the following front panel display:
Figure 5.8-1: Sweep mode display
1. Start Frequency
In this field enter the starting frequency for the sweep. You may enter from 0 Hz (DC) to 21.5 MHz in 0.01 Hz
steps.
NOTE: You are not allowed to enter a start frequency that is greater than the stop frequency.
2. Stop Frequency
In this field enter the ending frequency for the sweep. You may enter from 0 Hz to 21.5 MHz in 0.01 Hz steps.
NOTE: You are not allowed to enter a stop frequency that is less than the start frequency.
3. Linear / Log sweep
In this field select how the sweep frequency is incremented during the sweep. A linear sweep means that the
frequency is incremented by a constant amount for a given amount of time. A log sweep means that the frequency is
adjusted logarithmically between the start and stop frequencies as the sweep progresses.
To set Linear type sweep, press 1. To set Log type sweep, press 0. Pressing any arrow key or rotating the wheel
will toggle the sweep type between Linear and Log.
4. Continuous / Triggered sweep
In this field select whether the sweep is performed continuously or on a single event basis. If you select a
Continuous sweep, then the sweep is immediately restarted once the stop frequency is reached. If you select a
Triggered type sweep, then the sweep is halted once the stop frequency is reached. The sweep is not restarted again
until another trigger occurs. The trigger can come from three sources:
1. Pressing the Trigger key
2. Applying a low-to-high transition on the Ext Trig In connector
3. Sending an ASCII "T" to the RS232 port
The 4070A will simultaneously accept a trigger from all of the above sources. To set Continuous type sweep,
press 1. To set Triggered type sweep, press 0. Pressing any arrow key or rotating the wheel will toggle the sweep
type between Continuous and Triggered.
St: 1,000,000.00 Hz
Stp: 20,000,000.00 Hz
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