Technical data

The "Grot- C" scrambler must be installed in a room of an automatic telephone

exchange. It is remotely controlled from the "Grot" scrambler, works only in a pair with the

"Grotto" subscriber scrambler, and has a master key, identical to the key of the subscriber

scrambler. The additional individual key is not used. Other technical characteristics of the

"Grot-C" scrambler are similar to the parameters of the "Grot" scrambler.

There are two versions of the "Grot-C" scrambler produced: encased and non-encased.

The non-encased version has been designed for work in the structure of the MAK-16 module,

and must be installed on the city ATX.

The encased version of the "Grot-C" scrambler is installed at a local office automatic

telephone exchange, and provides protection for one subscriber line.

Power consumption – 2.5W maximum.

Power supply – 9V from a dc power supply included in the package.

Dimensions of the encased version of "Grot -C" - 115х200х30 mm.

Weight - 0.8 kg maximum.

AncVoice Coder – 2400 – a secure phone set

There is only one method of guaranteed protection of phone conversations against

eavesdropping – transmission of digitized voice data over telephone lines using special data

protection devices.

AncVoice Coder - 2400 provides a guaranteed protection against unauthorized access

to phone conversations. It has the following features:

Speech compression algorithm – based on the linear prediction model;

Unauthorized access protection algorithms – based on linear and parametric coding

methods with enabled additional transposition;

Duplex communication with the rate of speech transmission of 2.4 or 4.8 Kbps in

the asynchronous mode;

Syllabic intelligibility of synthetic speech at a rate of 2.4 Kbps - 86%, at 4.8 Kbps

- 92%;

Built-in modem data exchange protocols V.34,V32,V.22 bis;

Modem sensitivity - 43 dB;

Enabled storage of the key (password) in a programmable external device – the

non-volatile memory of Touch Memory buttons.

AncVoice Coder - 2400 possesses a large scope of service features of a conventional

phone set, due to:

Non-volatile memory for 16 phone numbers;

Last dialed number recalling and automatic redialing;

Speakerphone mode;

Pulse and tone dialing

Electronic clock, timing of conversations;

Adjustable volume

Microphone on/off