The Spectrum Application
FPC1000
74
User Manual 1178.4130.02 ─ 02
When you select the center frequency with the rotary knob or the cursor keys, the dis-
tance of each step that you take depends on the span. With the rotary knob, the small-
est possible step is a pixel. With the cursor keys, the step is 10
% of the span or one
division of the grid.
1. Press the "Freq" key to open the frequency menu.
2. Select the "CF Step Size" menu item to open the frequency step size menu.
3. Select one of step size options.
● "0.1 x Span"
The step size equals 10
% of the span or 1 division of the horizontal axis.
● "= Center"
The step size equals the center frequency.
This step size is ideal for measurements on harmonics. When you increase or
decrease the center frequency, the center frequency automatically moves to
the next harmonic.
● "Manual <x> Hz"
Define any step size you want.
This step size makes it easy to investigate a spectrum with frequencies at con-
stant intervals.
The R&S
FPC1000 adjusts the step size accordingly.
If you set the step size to 10
% of the span or to the center frequency, the
R&S
FPC1000 sets the step size internally. Manually defining the step size opens
an input field to define the step size.
Defining a frequency offset
A frequency offset allows you to shift the displayed frequency values by a certain
amount to a higher or lower frequency. This shift is an arithmetical operation only - the
measured frequency really remains the same.
Shifting the frequency to another value can be useful, for example, on frequency con-
verting DUTs such as satellite downconverters. You are then able to display the origi-
nal, unconverted input frequency of the DUT in the measurement results.
1. Press the "Freq" key to open the frequency menu.
2. Select the "Freq Offset" menu item.
The R&S
FPC1000 opens an input field to define the frequency offset.
3. Enter the required frequency offset.
TheR&S
FPC1000 adds the frequency offset to the center frequency you have
defined.
A blue dot at the center frequency label indicates that a frequency offset is active.
You can define positive frequency offsets in the range from 1
Hz to 100
GHz in
steps of 1
Hz. The maximum negative frequency offset depends on the start fre-
quency you have defined. The start frequency, taking the frequency offset into
account, is always ≥
0
Hz.
Frequency Configuration
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