BNC 835-3 User Manual - Manual (Page 19)

3 rd : dwell time in µ s, 4 th : off time in µ s).Values must be separated by semicolon!
Modulation Control
The 835-3 provides various modulation capabilities that can be accessed by the
MODULATION tab (Figure 11). On the left, the internal pulse modulation can be preset
and started with the ON/OFF button. Enter pulse width and modulation period in
milliseconds as required. Note that pulse width accuracy is approx. ±0.1 µs.
When external pulse modulation is used, the ext. Pulse Enable must be checked. Invert
the polarity of the external video signal by checking Inverse Polarity.
The internal AM can be enabled by pressing the ON/OFF button in the AM portion of the
submenu. Modulation depth can be selected from 1 to 99 %. AM modulation rate can be
set from 1 Hz to 10 kHz.
The frequency and phase modulation settings can be accessed by selecting tab FM/PM
(Figure 12). Enter the desired sensitivity per Volt for either frequency or phase
modulation and press the ON/OFF button. The BNC connector FM/PM on the rear
panel is now activated. Connecting the FM/PM input to the FUNCT OUT output by a 50 Ω
BNC cable generates internal modulation. The internal low frequency generator is used to
provide the modulation signal (see the chapter about the LF OUT control).
Figure 11 MODULATION tab for pulse and AM modulation
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