Rohde & Schwarz SMB100A - Pulse Modulation Settings

Instrument Function
R&S
®
SMB100A
179Operating Manual 1407.0806.32 ─ 13
signal input for internal pulse modulation. The polarity and input impedance of the con-
nector can be selected.
The pulse signal is output at the PULSE VIDEO connector at the rear of the instrument.
Automatic Level Control is deactivated with pulse modulation!
When pulse modulation is activated, the ALC state of the R&S SMB is automatically
changed to "ALC OFF" ("Sample & Hold"). In this state, the ALC loop is opened and the
output level is not regulated but the level modulator is set directly. In order to set the
correct output level, a sample & hold measurement is executed after each frequency or
level setting.
The level is decreased by 30 dB during "Sample&Hold" measurement.
5.4.5.1 Pulse Modulation Settings
To open the "Pulse Modulation" menu, select "Modulation > Configure > Pulse Modula-
tion" or use the MENU key under "Mod".
In the upper section of the menu, the modulation source is selected and the modulation
switched on. The configuration of the selected external and/or internal modulation source
is performed in the lower section of the menu.
The menu varies according to the selected modulation source.
In case of modulation source pulse generator, the settings for the pulse characteristics
and the trigger are offered in the "Pulse Generator" section of the "Pulse Modulation"
dialog. Option R&S SMB-K23 offers extended features, e.g. generation of double pulse
or selection of trigger mode. For description of the pulse generator dialog, see chap-
ter 5.5.4, "Pulse Generator", on page 194.
Additionally, you can use the internally generated Valid Signal for synchronizsation of the
pulse modulation, and assign this signal to the VALID SIGNAL connector. See also 
chapter 5.5.4, "Pulse Generator", on page 194 for description.
Modulation