31
Subject to change without notice
T y p e s o f M o d u l a t i o n
Example 1:
CH1—> modulation: fi rst pulse width 150 s
second pulse width 1.1 ms
period 2.5 ms (Fmod: 400 Hz)
CH2—> moduled signal (deviation: 2 kHz)
Example 2:
In this example, the external modulation signal is a ”trinary“
code composed of 9 bits. One bit is composed of 2 narrow and
/ or wide pulses, depending on the combination expected:
– A bit composed of 1 wide and 1 narrow pulses is called
OPEN.
– A bit composed of 2 narrow pulses is called LOW.
– A bit composed of 2 wide pulses is called HIGH.
For detecting the fi rst bit, a synchronisation bit (long low level)
is present. The modulation frequency is 20 Hz.
CH1—> modulation: narrow pulse of 200 μs
wide pulse of 1.8 ms
synchronisation bit of 14 ms
CH2—> zoom of CH1
CH1—> demodulated signal: DC coupled
CH2—> demodulated signal: AC coupled
The return to the modulation menu is possible by pressing the
PREV. key
and the return to the main display by pressing
the ESC key
.
The external modulation input is on the front panel (MOD. INPUT
). The signal can be of any shape, however the AM-depth and
FM/PM deviation programmed is calibrated only for a 2 V
RMS
signal at the input.
Types of Modulation
Amplitude modulation (AM)
After selecting D% (AM MEMU) using the context sensitive keys
, the display shows:
A new value of the modulation depth can be entered from the
data keypad
or modifi ed by the digital rotary
or by one of
the four context sensitive keys
.
The modulation depth may be changed from 0 to 100% with a
resolution of 0.1%.
The return to the previous menu is possible by pressing the
PREV. key
and the return to the main display by pressing
the ESC key
.
Example 3:
For AM sine (depth: 50%), the display shows:
