Rohde & Schwarz SMB100A - Enabling;Disabling Analog Modulations Using the MOD On;Off Key; Modulation Sources

Instrument Function
R&S
®
SMB100A
168Operating Manual 1407.0806.32 ─ 13
Amplitude, frequency and phase modulation are available for the basic unit (R&S SMB
+ frequency option R&S SMB-B10x) without additional equipment options. A standard LF
generator is provided for internal modulation. A Pulse Generator is provided by option
R&S SMB-K23. Option R&S SMB-K22, Pulse Modulation, is designed for instruments
equipped with frequency-options up to 6 GHz and R&S SMB-K21 for instruments with
high frequency options. Stereo modulation is available with option Stereo/RDS coder,
R&S SMB-B5.
Settings for the modulation are made in separate modulation menus. These menus can
be accessed in the block diagram by way of the "Modulation" function block, or by means
of the menu with the same name which is opened using the MENU key.
5.4.1.1 Enabling/Disabling Analog Modulations using the MOD On/Off Key
The MOD ON/OFF key switches the modulations on and off.
MOD ON/OFF
Press the MOD ON/OFF key to enable/disable analog modulations.
Pressing the key again restores the status that was active before the last switch-off. "MOD
OFF" is displayed in the info line of the header next to the "Level" field.
Remote command:
[:SOURce<hw>]:MODulation[:ALL][:STATe] on page 333
5.4.1.2 Modulation Sources
The following modulations use internal and external modulation sources:
●
Amplitude modulation
●
Pulse modulation
●
Frequency modulation
●
Phase modulation
Internal Modulation Sources
An LF generator and a pulse generator are available as internal modulation sources for
a fully equipped instrument. The LF generator supplies sinusoidal or rectangular signals.
The optional pulse generator (option R&S SMB-K27) provides single and double pulse
modulation with selectable pulse widths and periods or a user-definable pulse train.
See also chapter 5.5.1, "Overview of LF Generator", on page 187.
External Modulation Sources
The modulation inputs MOD EXT and PULSE EXT at the rear of the instrument are pro-
vided as the external modulation source for amplitude, pulse, frequency and phase mod-
ulation.
The external audio signal for stereo modulation is input via the analog L and R inputs or
via the digital S/P DIF interface at the rear of the instrument.
Modulation