7
. A superimposed DC component can be added to the output
signal by engaging the DC OFFSET switch (14) to enable
operation of the DC OFFSET control (5). Rotation of this
control adds a positive or negative DC component to the output
signal. The DC component introduced is independent of the
OUTPUT LEVEL control and can be varied by ±10 volts
open circuited or ±5 volts into 50 Ω. The DC Offset does not
affect the TTL/CMOS output jack. The effect of DC OFFSET
is shown in Fig. 3.
CONSIDERATIONS
1. Counterclockwise rotation of the COARSE frequency control
decreases the output frequency to approximately one-tenth of
the maximum for the range selected (10:1). For example, if the
10K range is selected and the COARSE frequency control is
set to full counterclockwise, the output frequency is
approximately 1 kHz.
2. It is advisable to set the FINE frequency control to the
approximate center of its rotation before setting the COARSE
frequency control. This assures that the FINE control will not
reach its limit while trying to finalize the frequency setting.
3. The FINE frequency control provides approximately ±5% fre-
quency deviation from the COARSE control setting. This
provides vernier adjustment to easily set the frequency to a
precise value.
4. When the 1Hz 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.
OPERATING INSTRUCTIONS
10
Figure 3. Use of DC OFFSET Control
5. When outputting square waves or when using the TTL
output, terminate the cable into 50 Ω to minimize
ringing. Also, keep cables as short as possible.