DIVEX Logo Helicom Saturation Control Unscrambler

Helicom Saturation Control Unscrambler


The SC HSU is designed for helium speech communications with the occupants of a two compartment saturation deck chamber. It also provides a bunk entertainment channel.

Operating Modes

  • The chamber attendant uses a master PTT for broadcast communications with Main Lock, Entry Lock and Bunk channels.
  • The chamber attendant uses an individual PTT switch for dedicated communication with each channel.
  • All channels have four wire communications with uplink signal priority and each is equipped with a dedicated volume control with minimum listening level.
  • All channels have independent uplinkand downlink signal volume controls to
    optimize communications.
  • Main lock and Entry lock channels connect to a chamber comms box and speaker box which consists of a loudspeaker, Electret microphone, volume control and push-button call facility for the occupants to call the chamber attendant. 3.5mm jack sockets also allow comms to be transmitted to a headset.
  • Bunks channel is configured with headset connection only and can be used for communications and entertainments, volume control is available to the earphones. There is also a push-button call facility.

A front panel loudspeaker allows the chamber occupants’ speech to be audible to the chamber attendant independently of his headset in all modes of operation. An on/off switch allows the loudspeaker to be switched off as required.

DSP Helium Speech Unscrambler Circuit Uplink signals from the chamber occupants are mixed in an audio mixer before decoding to the selected gas and environmental settings by a digital signal processing (DSP) circuit.

An LCD display is provided for monitoring helium speech decoding settings. Adjusting settings is easily accomplished by means of a front panel depth setting potentiometer calibrated 0 msw to 400 msw in 50 msw increments and a user-friendly keypad for PPO2, pitch reduction and temperature settings.

An unscrambler on/off switch allows the DSP helium speech unscrambler circuit to be bypassed when communications are in the air range or when unscrambling is not required

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In 2015 James Fisher Defence and Divex merged to form JFD.

Today, JFD serves customers in 81 countries across six continents.

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