Rohde & Schwarz EVSG-B1, Руководство пользователя

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Numeric Measurement Modes
R&S
®
EVSG1000
79 User Manual 1178.6227.02 ─ 06
Determines the carrier frequencies automatically, but only once. The frequencies do
not change automatically if the input signal changes.
For automatic carrier determination ("Autotune"): a new search is performed, see
"CRS/CLR Carr (Autotune function)" on page 78.
Note: Adapting the frequency in autotune mode.
The autotune function sets the measurement filter position such that the detected fre-
quency is in the center of the filter bandwidth. While the frequency is locked, the filter
position remains unchanged. If the bandwidth is narrow and the signal frequency
changes, e.g. due to changes of the transmitter, the signal may no longer be covered
completely by the measurement filter. In this case, the measurement results are distor-
ted. If you assume the ILS signal frequency might have changed, we recommend per-
forming a new search using the
Find Carrier function.
Remote command:
LLZ_START_FINDCARRIER
on page 281
GS_START_FINDCARRIER
on page 291
Carrier Thresh
Defines a threshold for automatic carrier determination. The measured power level
must exceed this level before the carrier frequency is adapted.
Remote command:
GS_CARRIER_THRESHOLD_DB
on page 287
LLZ_CARRIER_THRESHOLD_DB
on page 278
Upper Freq
The course and clearance carriers are defined as offsets to either side of the center
frequency. Which frequency is considered to be the course carrier - the upper or lower
frequency - depends on the used standard and the country it is used in. Thus, you can
swap the carrier definition if necessary.
Remote command:
SETUP:UNIT:UPPERFREQ
on page 253
Channel Frequency Configuration (CH FREQ)
Access : [CH FREQ]
Access VNC : [q]
The channel frequency determines the nominal frequency at which the measurement is
performed. For some avionics standards, the channels are associated with specific fre-
quencies. (See
Chapter A, "ILS Channel Frequency List" , on page 393 and Chapter B,
"VOR Channel Frequency List" , on page 395.)
CH ................................................................................................................................. 79
Freq ...............................................................................................................................80
Step Size .......................................................................................................................80
CH
Sets the receiver frequency channel on the active receiver board according to the
ICAO frequency list.
ILS Localizer and ILS Glidepath (GP) Modes