====== KCG-70 channel encryption unit ======
**Channel encryption unit KCG-70**; manufactured by [[Gretag]] together with [[Brown Boveri]].

The KCG-70 channel encryption unit allows the encryption of analogue voice or data communication via telephone and radio relay connections and also the recording and playback of encrypted messages using a tape recorder.

{{:images:gretag-kcg-70-bw.jpg?direct&600|Channel ciphering device KCG-70}}
===== Technical data =====
  * [[Principle]]: Digital ciphering system
  * [[Operation modes]]: Voice encryption, analogue data, digital data
  * [[Frequency range]]: 300 - 3000 Hz (voice), 300 - 2250 Hz (data)

==== Power supply ====
  * [[Mains operation]]: nominal 220 (187 - 253) volts AC
  * [[Batteries]]: nominal 24 (20 - 37) volts DC

==== Dimensions ====
  * Basic unit: 604 x 385 x 285 mm, 39 kg
  * Accessories case: 604 x 385 x 285 mm, 28 kg

==== Accessories ====

===== Operation =====
The KCG-70 channel encryption unit is used for the encryption of analogue voice or data communication via telephone and radio relay connections and also the recording and playback of encrypted messages via a tape recorder.

With the KCG-70, encrypted voice or data communication is possible via one or two opposing (duplex) channels, transmission can be by wire, microwave relay or a radio system with high transmission quality (FM); storage and retrieval of content from a tape recorder is also possible.

The KCG-70 consists of a basic unit with a modular design and a control unit (BEDI), which can be operated remotely via a cable up to a maximum distance of 30 metres.

It can be used on lines between ATf-53, LB-53 or PTT model 50 telephones, on microwave relay links, for example with [[R-902]] and with restrictions via FM radio connections; short-wave radio connections are not suitable due to transmission failures (fading, etc.).

The KCG-70 can also encrypt lines with analogue or digital data traffic (CCITT V.24).

Simplex or semi-duplex traffic can be used on two-wire lines or wireless connections (as with radio traffic, you must switch between "transmit" and "receive" using a push-to-talk button or on the control unit; a four-wire line is required for full duplex operation.

===== Technical principle =====

==== Components ====
The KCG-70 is fully solid state.

==== Development ====
The KCG-70 was developed by the crypto company [[Gretag]] (Dr Gretener AG) together with [[Brown Boveri]].

==== Use ====

{{gallery>:images?gretag-kcg-70*.jpg&0&80x80&lightbox&showtitle&titlesort}}

===== Technical documentation =====
  * {{ :manuals:gretag-kcg-70.pdf |channel-ciphering-device KCG-70}}

==== Further information ====