10
Sweep time parameter is displayed on the second line of the LCD display using a 4-digit value field and a decimal point, followed by
the measuring unit. The words “Sweep Time” will be displayed on the right of the second line to identify that the sweep time parameter
is shown. The unit will automatically display the output level 7 seconds after the last change of the sweep time value.
3.1.7. Sweep width setting (only for INTERNAL SWEEP mode).
This section describes the sweep width setting of the signal outputted on the
OUTPUT
jack when
INTERNAL SWEEP
mode is active
(INT LED and LIN/LOG LED are lighted).
Frequency sweep is performed by changing the output frequency within a range. The start frequency is always greater than the stop
frequency. The start frequency setting is performed by turning the
FREQUENCY
knob. The stop frequency represents a fraction of the
start frequency; the fraction set by turning the
SWEEP WIDTH
knob. The sweep width value is not directly obtained by turning a
knob; we must calculate it using the formula:
sweep_width
=
start_frequency
* [1 – 1/(
value_SWEEP_WIDTH_knob
)] [Hz]
where “value_SWEEP_WIDTH_knob” represents the value set by turning the
SWEEP WIDTH
knob.
The fraction of the start frequency can be set between 1 and 100 by turning
SWEEP WIDTH
knob, using 1-unit resolution (see Table
7).
Value Stop
frequency
Sweep
width Resolution Observation
1
Start frequency
0
Lowest value
100
(Start frequency)/100
0.99*(start frequency)
1
Highest Value
Sweep width parameter is displayed on the second line of the LCD display using a 3-digit value field and a decimal point followed by
the measuring unit. The words “Sweep Width” will be displayed on the right of the second line to identify that the sweep width
parameter is shown. The unit will automatically display the output level 7 seconds after the last change of the sweep width value.
3.1.8. Gate setting (only for FREQCOUNTER mode).
This section describes the gate period time setting used for measuring the signal frequency applied on
COUNTER IN
jack.
By pressing the range buttons,
UP and DOWN
, we can switch gate period time. There are 4 available period times for the gate: 0.01 s,
0.1 s, 1 s, and 10 s.
Gate period time is displayed on the second line of the LCD display. The mode identifier is displayed first, then the word “Counter”,
followed by the value of the gate period time.
3.2. Mode description
3.2.1. EXTERNAL VCG (External Voltage Control Generator).
This mode is used for generating an output waveform whose output frequency depends on the value set using the range buttons, the
FREQUENCY
knob, and the external positive DC level applied on VCG
SWEEP/COUNTER IN
jack. The positive DC value applied
on
VCG SWEEP/COUNTER IN
jack will cause the output frequency to decrease proportionally, with a ratio between 1:1 and 1:100
(for DC value between 0.0 V and +10.0 V, respectively).
3.2.1.1. Selecting EXTERNAL VCG mode.
EXT LED
lighting indicates active
EXTERNAL VCG
mode.
Otherwise there are 2 modes of selecting
EXTERNAL VCG
mode using front panel buttons depending on the current working mode
and the current value of
SWEEP INT/EXT
button.
Table 6: Sweep time range
Table 7:
sweep
width calculation
