TECHNICAL DESCRIPTION AND OPERATING MANUAL ST131 <PIRANHA II> and ST131N
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Set detection threshold
Threshold setting – thin red line – (In
indication -
)
is done, with 1dB step by
buttons and rotary encoder
rotation. Let’s set up threshold on 10dB higher then noise level (on
fig- NOISE=-88дБ) i.e. -78dB. This value is displayed on upper right
corner of the display.
Set peak average
Turn on previously created detailed template (see 3.9). “TEMPLATE” button will become red.
Activate spectrum analysis by pressing
.
Values at the upper right corner (052>045%) indicating: “052” –
number of detected signals, “045%” – percentage expression of
completeness of the process.
At the end of the analysis this place will be indicated like
on the figure: “001/78”, where 001 –first detected signal (cursor
will be placed there), 78 – total number of detected signals.
Signal frequency value is shown between extreme values
of frequency range – “125.000MHz” on figure, level – in “cursor”
field. On figure it is -063dB.
Save received list in memory of the device with using of “MEMORY”
submode (see 3.5).
For that press
, then
. After record number selection and pressing
record will
be saved.
Next move to the signal analysis
4.1.4.1.3 Signal analysis
Localization of a transmission source is a final stage of work. To get there, it is helpful to perform a
preliminary analysis of the signals in order to exclude non-hazardous signals. Features of the non-
hazardous signal in this case are following: no modulation, the demodulated sound of the television or
broadcasting station, some radio talks which do not have correlation with inside room talking.
All other modulated signals including "digital" signals should be treated as hazardous signals anyway.
In general, use of sound control, as a method of identifying STM is currently limited. A classical STM
is implemented by using analog modulation techniques (mostly, this is the frequency modulation) and
can be listened and identified, but in case of "digital" modulation there is no correlation between the
background sound and the digitally modulated signal.
For analysis start signal from the database should be called.
In case of manual signal database creation method, for calling signal list from memory,
being in “MEMORY” mode press
(see 3.5.2).
