Mobile suppressor of dictophones protection against wiretap of negotiations, MPD bugs

Assignment:

The mobile suppressor of dictophones is intended for prevention of record on a dictophone of the speech of the owner of the room.

Design, structure and operation principle:

Structurally MPD is executed in the metal case (see fig. 1). In an upper and edge wall loudspeakers are built in. In an edge wall there is a slot for connection of additional acoustic columns. On the opposite side governing bodies and slots for connection of two microphones and the charger are located.

Also two microphones, a cord for charging and the charger are included in the package of the device

The device creates an acoustic noise which does not allow to record a voice of the owner of the room.

The main difference of the device from other similar products is that the acoustic noise forms from a voice of the owner of the room. Therefore to filter it from the speech written on a dictophone it is not possible any modern means.

The device carries out suppression of all types of dictophones and "bugs", irrespective of their operation principle. The device is absolutely harmless in use and has no restrictions on application.

Preparation of the device for work:

Preparation of the device begins with accumulator charging. For this purpose the slot of charging, power supply toggle-switch which is close, joins a cord from the charger. The red LED over the slot of charging displays process of a charge of the accumulator. After a full charge color of a LED will change on green.

Before the first use of the device it is necessary to write a fragment of the speech of the owner of the device. For this purpose in any of two slots of a microphone input the microphone is connected. Over one of slots there is a record indication LED, and over another the record button. For record of a fragment of the speech any text from the book, or newspapers lasting 2 - 10 minutes undertakes. To start record, record for 5-6 seconds is clicked, the red LED of indication of record will not light up yet. The LED will burn 30 seconds during which the previous record of the speech is erased. Further in the microphone the prepared text becomes engrossed in reading it is desirable without pauses. The LED at the same time blinks in the red-green color. For the end of record it is necessary to click once again record for 1-2 seconds. At the same time the LED of indication will light up in the green color. The device is ready to work.

Further when using the device it is optional to write speech fragments.

Application order:

During conversation the device is installed on a table so that the loudspeaker on an edge panel was directed towards the interlocutor. The owner of the device warns the interlocutor about importance of a topic of conversation and need of inclusion of a security feature. Conversation is carried on in the microphone. From loudspeakers the rechepodobny noise sounds. The Rechepodobny noise forms in proportion to the level of the speech of interlocutors that provides comfort of negotiations. As the noise forms from earlier written fragment of the speech of the owner of the device, its maximum efficiency. The device can be used also without microphones. But process of masking is most effective it is reached at conversation via microphones.

In the second option of application microphones are not used. The device is installed in the room of negotiations. At the same time it is supposed that participants of meeting trust each other. It is necessary to muffle wiretap through it is reserved the set dictophones and "bugs" in a room interior. Level of an interfering signal becomes it that on a dictophone outside a table of meeting to sort the speech it was not represented possible. Unlike muffling of negotiations with the help of the TV or the radio receiver the noise of MPD is much more effective and it cannot be "cut" because of randomness of process of forming. In this option the additional column which input is connected in the connector on an edge panel can be used.

In the third option of use this device is placed in the car. The edge loudspeaker goes towards the interlocutor. As well as in the first option, the maximum masking of conversation will be reached during the work via the microphone.

Technical characteristics:

- The maximum power of a masking signal is 2 x 2,5 W

- Effective range of a masking signal of 160 - 4600 Hz

- The consumed current in the mode of average volume 370 mA

- Level of suppression of a signal of an akustozavyazka 36 dB

- Accumulator charging time 3 – 4 hours

- Time of continuous work in the mode of average volume 1,8 – 2 hours