TECHNICAL DESCRIPTION AND OPERATING MANUAL ST131 <PIRANHA II> and ST131N
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1
Signal level
2
Mark for manual pair selection
3
Pair number
4
Mark of automatic pair control
5
Numerical relative signal level value
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Feature of automatic level of signal control is to move the mark 4 to pairs of numbers with the
indication of the signal level in the pair, which is marked.
To manually select a pair, you must turn the rotary knob while 2 and 4 marks aligns vertically.
Pair selection is performed by turning the rotary knob.
Automatic installation of signal levels vertically relative to the noise level provides by
pressing the
button, manual selection is made by using
and
buttons.
If necessary, for detailed analysis of chosen pair press
button.
Connect wireline analyzer ST131.AWL to the telephone line gap (between telephone and
junction box).
On the main unit of ST131 «4-5» pair should be chosen (
- «4-5»)
If everything is connected properly, bright light of one of the «LINE» indicators on the top panel
of ST131.AWL should appear as well as tonal sound signal with lifted headset.
With lowered headset constant voltage on telephone line will be 48 (60) +/-10V, if lifted - 10+/-
5V («LINE» indicator dimly glowing)
To suppress interference signals with frequencies multiples of 220V - 50Hz signals from the
pulse power supply units, etc. connect pin 2 (Fig. 5) using a wire "Earth" to the ground bus.
In case of overload set lower value of amplifying level of input amplifier or chose automatic level
control (AUTO). In case of wireline control with put headset or unconnected pair don’t forget to set
maximum possible amplifying level.
Check this pair for acoustic sound signal with put headset. Sound which is corresponds with
room noise means presence listening device, which is using the given pair for data transfer. Wherein,
presence of other signal, digital for example, should be considered as dangerous and a source should
be found.
With lifted headset all unused pairs should be checked for signal presence.
Telephone should be checked in radiofrequency range using «RADIO» channel with range
difference control with lifted and put headset.
Security and firefighter alarm system lines
Security and firefighter alarm system sensors are convenient places for installation of
surveillance devices up to video cameras.
Same way as in the telephone line check for any analog or digital signal should be done.
In lack of «usual level» signals (from 100mV and more) on maximum amplification presence of
such devices as «passive» microphone (without power supply) or loudspeaker working in reverse,
microphone, mode should be cheked.
Fig. 52
5
