Setup Manual

Device View Description
R&S
®
Tx9
158Operating Manual 2109.9110.02 ─ 07
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Operation with reference frequency
Here the transit frequency is stabilized by means of a reference frequency. The fol-
lowing options are available:
–
External 10 MHz reference frequency
– External PPS (pulse per second)
– Built-in GPS receiver.
The frequency stability and frequency accuracy which can be achieved in this way
fulfill the increased requirements for operation of the transmitter in single‑frequency
networks. If several reference signals are available at the same time, automatic
selection of the most suitable reference frequency is possible.
If the reference signal fails, the transmitter switches over to Holdover Mode and fre-
quency control operates with the accuracy of the temperature‑stabilized 10 MHz crystal
oscillator (OXCO).
Since, in Holdover Mode, frequency control becomes increasingly inaccurate over
time, the output signal of the exciter can be switched off after a configurable Guard
Time.
In the case of reference signals with major fluctuations (jitter), e.g. with non‑controlled
external GPS receivers, a jitter correction function can be activated.
For measuring purposes, the used reference signal or one of the reference signals pro-
cessed internally in the exciter can be output via the Monitor-Out socket (X24).
"Frequency Regulation" parameters
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Path:"Device View (Home)" > "Tx<n>" > "Exciter" > "Frequency Regulation" > Tab
"Frequency Regulation"
Name Description Value range Access right
Ext. 10 MHz (Input) Indicates whether an external 10 MHz reference is
present at the REF_IN (X64) socket on the R&S
TCE900.
No Signal,
Inaccurate,
OK
Read only
Source (Input) The suitable signal source for the frequency reference
can be either detected automatically or preselected in
this list. If multiple signal sources are connected simul-
taneously in "Auto" position, an external reference is
given preference for selection before the internal GPS.
In "Manual" position, the internal crystal oscillator
(OCXO) is calibrated manually and the transmitter can
be operated completely without an external reference
source (not suitable for single-frequency networks).
Manual, Ext.
5 MHz, Ext.
10 MHz, Ext.
PPS, Int.
PPS GPS,
Auto
Read only
Ext PPS (Input) Indicates whether a seconds pulse is present at the
1PPS_IN socket (X23) at the R&S TCE900.
No Signal,
Inaccurate,
OK
Read only
Current Source (input) Shows the signal source used currently for frequency
regulation.
Manual, Ext.
5 MHz, Ext.
10 MHz, Ext.
PPS, Int.
GPS
Read only
Exciter ATSC