2825R-XX SERIES TWO DIVER RACK
MOUNT COMMUNICATOR USER MANUAL
282XR-UM
REV 5.0
19
tender to diver conversation and diver to tender conversation for proper record
levels.
4.8 Options
DSP3 Helium Speech Unscrambler Option
4.8.1
The DSP3 Helium Speech Unscrambler option is located on right side of the
communicator and accommodates a wide range of operating depths. This state-of-
the-art digital design can accommodate a multitude of functions ranging from the
correction of the diver’s raw helium speech to normal intelligible voice levels,
advance treble boost and complex noise reduction filters (NRF).
Communicators configured with this option are only supplied with the AC power
option. This is due to the power requirements of the Unscrambler option. The radio
can be operated in the air mode by turning the HSU off.
Amron’s advanced NOISE REDUCTION FILT
ER (NRF) incorporates a complex
DSP algorithm which filters out background noise while allowing the diver’s speech
to be clear and intelligible. Amron’s NRF automatically captures the frequency
spectrum of applied background noise within the audio frequency bandwidth and
reduces it without affecting the diver’s speech.
The Treble Boost Control provides a means of adjustment to enhance the diver’s
microphone performance. The treble boost feature allows for optimum frequency
enhancement and improved intelligi
ble speech from the diver’s voice.
The Depth Control is used to change the amount of shift in the frequency of the
diver’s voice. The depth control is advanced as the diver’s depth increases. There
is a certain amount of interaction between the controls, and also a difference
between diver voices, therefore it is necessary to tune the unit to the diver.
Intelligibility is the desired result; each operator will find a combination which works
best. The frequency shifting algorithm changes the amount of correction to the raw
helium speech. The Depth Control is a multi-turn control with a locking feature. This
allows the tender to finely adjust the level necessary and lock the control to prevent
accidental adjustments.
At power-up, all the controls should be in the minimum (far left) position. Have the
diver speak and adjust the DEPTH CONTROL as necessary to achieve the best
speech quality. Then adjust the TREBLE BOOST as necessary to improve the
quality. There is some interaction between these controls so you may have to go
back and adjust the DEPTH CONTROL. Once the best speech quality settings are
found, the NOISE REDUCTION FILTER can be adjusted, if necessary, to reduce
any background noise.
Operating in 2-Wire and Full Duplex (4-Wire) modes are possible with the HSU. In
2-Wire mode, the tender's push-to-talk switch interrupts signals from the diver. In
Full Duplex mode, the tender will hear the diver at all times and tender must use a
headset to talk to the divers without using the push-to-talk switch. Use of a headset
to monitor helium speech is strongly recommended to enhance intelligibility.
Summary of Contents for AMCON II 2825R Series
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