07 April 2022

Easitalk™ - Advanced and innovative DSP noise reduction feature by Codan

Easitalk

Easitalk (easytalk) is a feature of NGT transceivers that removes noise and interference from incoming voice signals. Easitalk works by applying Digital Signal Processing (DSP) techniques to incoming voice signals. These techniques are similar to those used with digital mobile telephones and satellite telephones.

Easitalk is simple to use because it is integrated into the transceiver - it is not in a separate unit. No tuning is required, just an on/off control.

Listening trials indicate that Easitalk outperforms other noise reduction products, and it has been successfully trialled with a wide range of languages.

By integrating speech processing within the transceiver, Codan has not only made speech processing more effective but, more importantly, has made it useful in the hands of the user. For the first time, mobile users will now be able to enjoy the benefits of noise reduction technology.

Hear the difference ... The same transmission was received by two HF tranceivers, one with Easitalk enabled and the other, without. Both transceivers were connected to the same antenna.


No Easitalk


This is typical HF radio containing both voice and a large amount of background noise. The average signal (shown as a lighter colour) is fairly even indicating that the voice signal is not any more prominent than the background noise.




Codan advanced DSP noise reduction (Easitalk
)

Easitalk has removed much of the background noise and the average signal (shown as a lighter colour) displays a form much more like a voice waveform with highs and lows.



Does Easitalk offer any benefits over Lincompex? 

Yes. In networks that use Lincompex (LINk COMPression and EXpansion), each system in the network needs to be equipped with Lincompex software. With NGT, a single transmitter with Easitalk can be used within a network and still be able to communicate with other systems, but those systems won’t benefit from the features of Easitalk. 

For a continuous signal, Lincompex provides no discernible improvement over any other compression scheme. During inter–word quiet periods, the Lincompex receiver effectively prevents background noise levels from rising (this provides Lincompex’s apparent improvement). During continuous or substantially continuous speech, no improvement is noted. 

Under poor conditions, interfering signals may distort the recovered Lincompex control signal. Under very poor conditions the control signal cannot be properly decoded and the signal recovery mechanism breaks down completely. 


73 - Petr, OK1RP

1 comment:

  1. On USB the EasiTalk works perfectly. The DSP noise reduction algorithm is aggressive but the modulation is almost not affected just background noise is suppressed effectively.
    I realized that EasiTalk is magic feature even also on CW! The audio on CW is smooth and beautiful.

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