A test report on the multidimensional listening experience with the IKΩS IMPULSE

This test report is all about the IKΩS IMPULSE, an innovative device that can take your amateur radio experience to a new level. The author, engineer Jürgen Mothes (DL7UJM), takes you on an exciting journey and explains what the 3D phase shifter is all about and how it can improve your audio experience.

How the IKΩS IMPULSE enhances radio sound

Delaying a mono audio signal is a tried and tested studio technique for creating a quasi-stereo signal. The mono signal is played back as the left channel, for example, and the delayed signal as the right channel, resulting in an apparent stereo sound impression. In professional studio technology, this involves an effort that would certainly be oversized for radio technology with its limited AF frequency range. This is where the IKΩS IMPULSE comes in, which the manufacturer describes as a "3D phase shifter for a better audio experience".

Connection in seconds: It's so easy to integrate the IKΩS IMPULSE into your wireless station

The small device with housing dimensions of 105 x 30 x 85 mm (width x height x depth) is sure to fit on any station table. Connection to a receiver or transceiver is very simple: The input jack of the IKΩS IMPULSE is connected to the headphone socket of the receiver or transceiver using the supplied jack cable (6.3 mm stereo plug). Any necessary adapters to 3.5 mm jack plugs are included in the scope of delivery, as is the power supply cable. The power supply cable has an open end for connection to a DC voltage. It requires 9 -16 V at 30 mA. Due to the low current consumption, the device could also be connected to a switched DC voltage output of a transceiver.

Stereo headphones are connected to the output socket of the IKOS. The desired listening impression can only be achieved with stereo headphones. More on this later.

The IKΩS IMPULSE does not have a true bypass. It must remain connected to the power supply even when switched off. This is indicated by a small green LED.


Sensitive control and subjectively better hearing: My experience with the IKΩS IMPULSE

Now I was curious to see how the IKΩS IMPULSE would behave on the transceiver. First, I searched for a CW signal. Then set the AF volume to the first third, the effect switch initially remains on "Off". As expected, the receiver signal can be heard normally.

Now turn the delay control to the left stop and the switch to "On". A quasi-stereo CW signal can be heard in the headphones. The volume is subjectively somewhat higher, the signal is slightly louder on the left headphone than on the right. For me, this is a very pleasant sound. Turning the delay control to the right causes the reverberation in the right headphones to increase to an echo. The stronger reverberation then makes the CW signal illegible. This requires sensitivity according to the CW speed. The behaviour is similar with an SSB signal. The delay control can be sensitively adjusted and you will quickly find your personal "sound". In the manual, the manufacturer states that the quasi-stereo signal prevents fatigue during prolonged listening. I have listened to the pileup of a highly popular GMA station as a test and can confirm this for myself. The receiver signal sounds subjectively wider and clearer.

Optimised for SSB voice signals - technical data and mode of operation

The AF frequency response of the IKΩS IMPULSE is adapted to that of an SSB voice signal. The device is not intended to influence the frequency response or an interference signal.

Another note on transceivers with a second receiver: Despite a stereo jack cable, only the signal from the main receiver reaches the IKOS. If you want to hear the signal from the second receiver at the same time, it must be switched to the headphone socket on the transceiver (often referred to as "Mix").

Not just for headphones: use with stereo PC active speakers

In the picture I have shown the oscilloscope delay between the left and right headphones. With a CW sampling rate of 20 WpM and the delay control set to the right, the pause between the original signal and the delayed signal is approx. 85 ms. By the way: A stereo PC active loudspeaker can also be used on the IKΩS IMPULSE instead of headphones.

Source: https://zeitnitz.eu/scope_en Software is for private use only!


Significantly improves the sound image when receiving mono signals with headphones.

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