R&S FSH
Spectrum Analyzer Mode
Configuring Spectrum Measurements
Operating Manual 1309.6275.12 - 14
89
In the frequency domain, the R&S FSH would never start a measurement with the
video trigger because there is no guarantee that there is a signal that generates
video voltage present at the start frequency.
C
External Trigger
(rising or falling slope)
A sweep starts on the rising edge (RISE) or on the falling edge (FALL) of an
external trigger signal. The external trigger signal is fed in via the BNC connector
"Ext Trigger". The switching threshold is 1.4 V, i.e. a TTL signal level.
C
Gated Trigger
When the gated trigger is active, a gate signal that is applied to the R&S FSH
trigger input controls the sweep. The R&S FSH starts measuring when the applied
gate signal becomes active and the set gate delay has expired, and it interrupts the
measurement as soon as the defined gate length is reached. With the gate signal
becoming active the next time the measurement is resumed etc.
Pulsed signals can be measured by this method, if the gate delay and gate length
are selected in a way that the measurement is only performed while the pulse is
active. Gated measurements are possible in the frequency domain (span > 0) and
the time domain (span = 0), but it is available only in combination with an external
gate signal.
M
Press the SWEEP key.
M
Press the "Trigger" softkey.
The R&S FSH opens a submenu to select the trigger source.
M
Select the trigger source you need.
The R&S FSH activates the trigger.
Including a Delay Time
When you are using a video trigger in the time domain or an external trigger, you can
delay the start of the measurement with respect to the trigger event by entering a delay
time. In this way, you can include time differences between the trigger event and the
measurement.
The range of the trigger delay is from 0
Y
s to 100 s. The resolution depends on the
subrange.
Trigger delay
Resolution
0 to 1 ms
10
Y
s
1 ms to 10 ms
100
Y
s
10 ms to 100 ms
1 ms
100 ms to 1 s
10 ms
1 s to 10 s
100 ms
10 s to 100 s
1 s
