7.4 fLow & fHigh
(Start- & Stop frequency)
fLow
(start frequency) sets the frequency where the sweep should begin, whe-
reas
fHigh
(stop frequency) sets its ending frequency. By choosing these two
parameter, the complete
frequency range
which will be sweeped is defined.
Please note that a large frequency range will badly squeeze the display hori-
zontally (in the X axis) and thus significantly reduces measurement accuracy.
Individual signals, especially when close together, will often not be distinguisha-
ble anymore. However, if you narrow the frequency range, you will be able to
analyze the sweep range
more precisely
. You will be able to see far more
details and
higher accuracy
. A large frequency span is thus mostly useful for a
broad overview,
not for exact measurements
.
7.5 RBW
(Bandwidth)
[Key 9]
By adjusting
bandwidth
, you can adjust detail clarity and sensitivity at the same
time. When
bandwidth
is setted at a very high value or even FULL, the sweep
will be very fast, however, the display becomes comparatively inaccurate and
sensitivity is low. Hence, very weak signals will not be picked up anymore. The
smaller the
bandwidth
, the longer the sweep will take, but the display will be
more precise and weaker signals can still be displayed. Thus, for example, a
single signal initially sweeped with high
bandwidth,
can turn out to be a number
of several narrow, close together signals. However, this gain in accuracy has its
disadvantage in the far longer sweep times.
HINT:
To accelerate measurement of small frequency ranges with extremely
small filters,
DFT
-FFT mode is
automatically
activated when using a SPAN bet-
ween
10-200Hz
and a
0,3Hz
,
1Hz
or
3Hz
filter. Thanks to this mode,
signifi-
cantly
faster sweep times can be achieved in spite of extremely narrow filters.
Firmware V 1.0 / © 2005-2013 by Aaronia AG, D-54597 Euscheid, www.aaronia.com
24
fLow
(Start-Frequency)
fHigh
(Stop-Frequency)
RBW
(3Hz)
RBW
(300Hz)
7.0 The main menu
