TECHNICAL DESCRIPTION AND OPERATING MANUAL ST131 <PIRANHA II> and ST131N
50
In the FULL RANGE mode the pulse sequence with a pulse width of 0.1 ms and a duty ratio of
1:1 with no gaps are detected but when duty ratio of 1:100 the detection time will be about 30 seconds
and for duty ratio of 1:1000 - more than 500 seconds.
Pulse width 0.1 ms at a duty ratio of 1:100 corresponds to the DECT network parameters and
is close to 2G network.
Reducing the analysis bandwidth increases detectability. So when the band is 10MHz or less and
duty ratio of 1:100, the detection time will be less one second.
If there is information about the carrier frequency of the radio pulse is advisable to use the
"PULSE" option specially designed to detect the sequence of radio pulses. Maximum band simultaneous
analysis is 60 MHz and a maximum duration of the screen visible signal is equal 200 ms.
When using "PULSE" option, pulse sequence with a pulse width of 0.1 ms at a duty ratio of 1:1
and 1:100 are detected without time gap (when “MAX TIME” option value and the time scale value
are maximum).
To activate it, being in the FULL RANGE mode switch to auxiliary context buttons (pressing the
rotary knob) and press
. Next step:
• Set the center frequency repeatedly pressing on
to chose the "FREQ" item and further rotation
of the rotary knob to set the desired frequency. Frequency step is selected in the pop-up list after
pressing the
button.
• Select the maximum duration of the signal from the pop-up list after pressing the button
.
Check the correct installation, in the time scale should be 210 ms. Otherwise, pressing the
select
the "HORIZON" item and rotate the rotary knob to the proper setting.
At maximum value of the “MAX TIME” option the device’s reaction to click slows down to one
second. Selecting that maximum time allows the user to choose
between the detection and correct representation of pulse
sequences with short pulse duration and correct representation of
pulse sequences with long duration. Press the
or
button
once to cancel the automatic waveform alignment relative to the
center of the screen. The "AUTO" sign in the upper right corner
will disappear. Press
, then select and rotate the rotary knob,
set the threshold level to the required position.
• Press
and select
. The appearance of the inscription "WAIT ..." informs that
the device is waiting the rising edge pulse to exceed the threshold level.
Figure 45
