TECHNICAL DESCRIPTION AND OPERATING MANUAL ST131 <PIRANHA II> and ST131N
43
Thus, for example, to detect 10µW transmitter being at the center of the circular room with a
radius 10 meters must select a span of not more than 10 KHz or if the transmitter power will be 1 mW,
it is sufficient 100 MHz band.
You can see the situation from the other side. Increase the frequency band with keeping the
predetermined sensitivity. In this case you need to move the antenna along the surveyed interior at a
certain distance and at a certain interval. For example, if you chose the 100 MHz band this distance
should be no more than three meters. This means that every three meters need to stop and scan a
given band with selected frequency range (very conditional each stop will take about ten minutes). Or,
subject to the antenna and ground surfaces, use the FULL RANGE mode. In this case there is no need
for intermediate stops, however, the high probability of missing signals from the transmitters of less
than 10 µW take place.
4.1.4.1.1.3 Choosing detector.
To search for radio signals with unknown parameters, there is obviously preferable to use a
peak-hold detector. Choose a peak-hold detector with
and then pressing the "PEAK" item. A
classic application of this detector is the retention (accumulation) of spectrum peaks when needs a fixing
fact of rare occurrence of a single signal or pulse sequence with unknown time of its appearance. When
searching for signals with unknown parameters its use avoids of passing variable time signals (reset of
accumulation results by pressing
). A “clog” of the spectrum is possible with this kind of detector.
4.1.4.1.1.4 Detailed template creation.
See 3.9.2
After presetting go to potentially dangerous signals database.
4.1.4.1.2 signals database creation
As it is seen from fig. 44 there are two main ways – manual and automatic. Given database
represents a set of signals, exceeded the predetermined threshold.
Formally, these signals classification – demodulation etc. is done in next step – signal analysis, but of
course, with manual work these actions can be combined.
Cost and time estimates with using of different primary database creation methods
Extreme cost and time estimates variants are presented. Depending on work specifics combination of
these variants are possible.
4.1.4.1.2.1 Manual signal database creation method
For using of this method press
. Next, place the cursor on interested signal and press
Signal will be saved.
It must be noted, that there can be only one list of this kind, unlike from AUTOMATIC ANALYSIS
result lists.
4.1.4.1.2.2. Automatic signal database creation method
For automatic signal creation, for example, being in “full Range” mode press
. Device will
go to “Automatic analysis” submode. (see 3.4)
