HF voice encryptor AT F1800

We present an AT F1800 voice encryptor for HF transceivers.
It enables transmission of digital voice over HF channels through an ordinary SSB transceiver.
HF encryptor uses the new technology that makes it possible to have a reliable high quality digital voice communication under conditions of interference, distortions and Delinger fading that are specific to HF communication channels.

Either of the two built-in vocoders MELP1200 or MELP2400 can be used in AT F1800. The bitrate of MELP1200 is 1200 bps, its voice recognition is less if compared to MELP2400, but its performance is better in adverse conditions of radio communication passing.
Autodetect function permits to receive both digital and ordinary analogue signals. Transmission mode (digital or analogue) is activated by a toggle switch at the encryptor rear panel.
AT F 1800 encryptor is connected to HF transceiver by means of a standard accessory connector. Voice receiving/transmitting is done via an ordinary IT headset for PC with two 3.5 mm jacks. Wired PTT (Push-To Talk) button sets the transceiver for transmission.

Thus, connection to HF transceiver is done without any modification of the latter.
AT F 1800 encryptor is programmable.
The programmable parameters are — RX and TX audio signals levels, PTT level, selection of MELP1200 or MELP2400 vocoder, values up to 16 encryption keys, etc.
Each key length is 32 bit (4,294,967,296 combinations). Programmed keys are changed programmatically or by means of a DIP switch.

AT F 1800 is programmed via a PC USB port. Software is included in the delivery set.
*AT F 1800 HF encryptor is designed for state organisations and structures (use of encryption, 16 keys, more than 4 billion keys combinations).

AT F 1800 specifications