SYSTEM Functions (SYS Key)
R&S FS300
E-1007.9900.15
6-168
Operating manual, 02/2006
6.3.4.2
Selecting an Internal or External Reference Source
Use
The R&S FS300 acting as the frequency standard for all internal oscillators
can use the internal reference source (
internal
) or an external reference
source (
external
). A 10 MHz crystal oscillator is used as the internal refer-
ence source. When the default setting is activated (internal reference), a
10 MHz frequency is output at the REF OUT rear-panel connector [23] to
synchronize other devices to the R&S FS300 reference frequency, for exam-
ple.
When the “REFERENCE external” setting is activated, the REF IN connector
[22] is used as the input for an external frequency standard. All the R&S
FS300’s internal oscillators are synchronized to this external reference fre-
quency (also 10 MHz).
Selecting the
reference source
1.
When required, connect the external reference source to the REF IN
connector [22].
2.
Press the
function key
in the
menu
.
The current reference source setting is displayed.
3.
Press the
ENTER key
A selection field containing the available settings is displayed. The de-
fault setting is “internal”.
4.
Select a reference source with
rotary knob
5.
Press the
ENTER key
The setting is saved and the R&S FS300 frequency standard is taken
from a new source.
NOTE
If there is no reference signal when you switch over to an external reference,
the message PLL UNLOCK is output after a short delay to indicate that there
is no sync.
Summary of Contents for FS300
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