R&S FSMR, Operating Manual

Page: 214 / 955

Level Display / RF Input R&S FSMR
1166.3363.12 4.7-4 E-2
AMPT – NEXT menu:
REF LEVEL
POSITION
The REF LEVEL POSITION softkey allows the reference level position to be
entered.
The setting range is from -200 to +200%, 0% corresponding to the lower and
100% to the upper limit of the diagram.
IEC/IEEE-bus command:
DISP:WIND:TRAC:RPOS 100PCT
REF LEVEL
OFFSET
The REF LEVEL OFFSET softkey allows the arithmetic level offset to be
entered. This offset is added to the measured level irrespective of the
selected unit. The scaling of the Y axis is changed accordingly.
The setting range is ±200 dB in 0.1 dB steps.
IEC/IEEE-bus command:
DISP:WIND:TRAC:RLEV:OFFS -10dB
GRID
ABS REL
The GRID ABS/REL softkey switches between absolute and relative scaling
of the level axis.
G RID ABS is the default setting.
ABS The labelling of the level lines refers to the absolute value of the
reference level.
REL The upper line of the grid is always at 0 dB.
The scaling is in dB whereas the reference level is always
in the set unit (dBm, dB
µ
V,..).
For setting RANGE LINEAR (linear scaling, labelling of axes in %) the softkey
is not displayed since the unit % itself implies a relative scale.
IEC/IEEE-bus command:
DISP:WIND:TRAC:Y:MODE ABS
RF INPUT
50 75
The RF INPUT 50 / 75 softkey switches the input impedance of the
instrument between 50 (= default setting) and 75 .
The setting 75 should be used if the input impedance (50
)
is transformed
to 75 using the corresponding adapter unit of type RAZ (= 25 in series to
the input impedance of the analyzer). The correction value used for the
adaption is 1.76 dB = 10 log ( 75 / 50 ).
All levels specified in this operating manual refer to the default setting of the
instrument (50
)
.
IEC/IEEE-bus command:
INP:IMP 50OHM