Configuration
R&S
®
FSW-K7
92
User Manual 1173.9240.02 ─ 23
AC coupling blocks any DC voltage from the input signal. This is the default setting to
prevent damage to the instrument. Very low frequencies in the input signal may be dis-
torted.
However, some specifications require DC coupling. In this case, you must protect the
instrument from damaging DC input voltages manually. For details, refer to the data
sheet.
Remote command:
Impedance ← Input Settings
For some measurements, the reference impedance for the measured levels of the
R&S
FSW can be set to 50
Ω
or 75
Ω
.
Select 75
Ω
if the 50
Ω
input impedance is transformed to a higher impedance using a
75
Ω
adapter of the RAZ type. (That corresponds to 25
Ω
in series to the input impe-
dance of the instrument.) The correction value in this case is 1.76 dB = 10
log (75
Ω
/
50
Ω
).
This value also affects the unit conversion (see
This function is not available for input from the optional Digital Baseband Interface or
from the optional Analog Baseband Interface . For analog baseband input, an impe-
dance of 50
Ω
is always used.
Remote command:
5.3.3.2
Amplitude Settings for Analog Baseband Input
Access
: "Overview" > "Amplitude"
The following settings and functions are available to define amplitude settings for input
via the optional Analog Baseband Interface in the applications that support it.
The input settings provided here are identical to those in the "Input Source" > "Analog
Baseband" tab, see
Chapter 5.3.1.4, "Analog Baseband Input Settings"
Input and Frontend Settings
