Technical data

Method of encryption – mosaic array: timing transpositions and frequency

inversion;

High quality of reconstructed speech.

Encryption algorithm:

Open key distribution method allows to work without a set of manual switches;

Total number of key combinations - 2х10

;

The length of a key combination - 61 bit;

The scrambler automatically generates a random session key, which is used for

one session only and is automatically deleted from the memory of the scrambler as

soon as the communication session is over;

The session key is not transmitted into the line, and, therefore, cannot be

intercepted.

Channel work:

Duplex communications mode;

Compatible with any phone or fax machine (G2, G3 CCITT) with pulse or tone

dialing, that have an analogue interface and comply with the following

requirements;

Compatible with any mini-ATXX or PBX with analogue output;

Presence of an echo canceller, automatically adjusting to the parameters of subscriber's a

telephone set, subscriber's line, nonlinearity and fading of paths;

Stability of operation in real-life telephone channels, including inter-city and international

channels with satellite and radio-relay inserts and any kind of multiplexing.

Technical characteristics:

Voltage in the subscriber line in the waiting mode: from 30 to 60 V;

Input impedance at the input of the subscriber phone line, with the effective frequency

range between 0.3 ant 3.4 kHz: in the secure communication mode - between 450 and 800

Ohms; in the call waiting mode – at least 10 kOhms; in the calling mode – at least 4

kOhms;

Voltage drop on the line input in the secure communications mode, depending on the

amperage in the line: 15 mA – between 4 and 11.0 V; 20 mA – between 5.5 and 11.5 V;

30 mA - between 6.0 and 13.5 V; 40 mA - between 6.2 and 15.0V;

Input DC impedance in the pulse dialing mode: if the loop is opened and the feed

amperage is 35 mA - 100 Ohms maximum; if the loop is closed and the feed voltage is 60

V - 200 kOhms maximum;

DC power consumption on the line input in the waiting mode – 0.5 mA maximum, in the

secure communications mode - between 25 and 40 mA;

Signal/noise ratio at the line input of the scrambler, for which a 50% of syllabic

intelligibility and a stable synchronization is provided- at least 26 dB;

Maximum amount of time required to switch in the secure communications mode: 40 sec

for SCR-M1.2, SCR-M1.2mini, SCR-M1.2multi, 30 sec for the "Grot" and "Grot-C";

Voice signal delay in the secure communications mode: 0.5 sec maximum for SCR-M1.2,

SCR-M1.2mini, SCR- М1.2multi; 0.25 sec maximum for the "Grot" and "Grot-C";

Power supply for the scramblers: single-phase 198-242V AC, 48-60 Hz.