====== SVZ-B: Wideband Voice encryption unit ======
**SVZ-B** or wideband voice encryption unit; manufactured by [[Crypto AG]], Zug.

For many years, the American made [[SE-227]] and [[SE-412]] radios had to be used without encryption; code tables, obfuscation lists and "coded speech" had to be used to make the content of a message incomprehensible to third parties.

The situation changed when the SVZ-B digital voice encryption unit was introduced in 1984: the SVZ-B allows fully encrypted and cryptographically secure communication.

{{:images:endgeraete-svz-b-open.jpg?direct&600|SVZ-B}}
===== Technical data =====
  * [[Principle]]: Bitstream ciphering
  * [[Operation modes]]: crypto - clear
  * [[Frequency range]]: Wideband interface 30 - 6000 Hz, audio interface 300 - 2400 Hz

==== Power supply ====
  * [[Batteries]]: 10 - 30 V DC

==== Dimensions ====
  * 285 x 68 x 280 mm, 4.0 kg

==== Accessories ====
  * Relay control units [[RAS-227]] and [[RAS-412]] for encrypted communication via relays.

{{:images:endgeraete-svz-b-open-front.jpg?direct&600|SVZ-B}}
===== Operation =====
The SVZ-B can be connected to the [[SE-227]] and [[SE-412]] wireless sets via the X-Mode wideband interface, the RAS-227 and RAS-412 relay switching sets allow direct relay operation without switching, the previous CX-4656/GRC relay cables could no longer be used on encrypted SE-227 relay connections.

Two keys can be entered on the SVZ-B using the numeric keypad and the user can easily change between both of them; a NiCd battery is used to keep the memory contents when the set is powered off.

The SVZ-B is connected to the transceiver with a 19-pin plug. The [[microtel]] is connected at the top left, next to the volume control to the right. The switch underneath can be used to switch between clear mode, key 1 and key 2.

The two stored cryptological keys can be deleted by pressing the key combination 0 and * or they are automatically deleted when the set cabinet is opened.

===== Technical principle =====
{{ :images:endgeraete-svz-b-block.jpg?direct&350|SVZ-B}} The audio signal is converted into a 9 kBit/sec data stream using adaptive pulse code modulation (APCM); together with synchronisation pulses, this results in a 9.6 kBit/s data stream.

The key generator generates pseudo-random numbers at the same speed, they are mixed with the data stream and fed to the transmitter via the X-mode interface.

The coded signal, which can only be perceived as noise, is mixed on the receiver side with the same pseudo-random number data generated by the key generator, resulting in a data stream identical to the original audio signal, which is converted into an audible audio signal by a digital-to-analogue converter.

==== Components ====
{{ :images:endgeraete-svz-b-closed.jpg?direct&400|SVZ-B}} The set is completely solid state.

==== Development ====
The SVZ-B was developed by [[Crypto AG]] in Zug in 1980/84.

The remote-controlled SVZ-B L Flz was developed as an alternative for light aircraft and helicopters.

==== Deployment ====
The sets were procured in 1983/84 and were in service with the troops from 1986 until 2002; they were widely used in radiotelephony, as standard, only network subscribers with increased security requirements were equipped with the classified SVZ-B.

Due to the classification, the sets did not end up in collector's hands after being liquidated.

{{gallery>:images?endgeraete-svz-b*.jpg&0&80x80&lightbox&showtitle&titlesort}}

===== Technical documentation =====
  * {{ :manuals:svz-b-regl.pdf |The voice encryption add-on broadband (SVZ-B), Regl 58.146d}}
  * {{ :manuals:svz-b-anleitung-diagnostiker.pdf |Voice encryption add-on broadband (SVZ-B), instructions for diagnosticians, Regl 65.525IId}}

==== Further information ====
  * [[https://www.hamfu.ch/de/geraete/geraet.php?id=121|SVZ-B on the Hamfu website]]