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These sources of power line noise include all kinds of switching loads attached to your grid*. Light dimmers based on semiconductor controlled rectifier techniques are as notorious as motor controllers that power loads on and off at different phases of the AC cycle. DC/DC converters inject asynchronous periodic noise into the power lines. And let’s not forget the massive power transformers as those big things in our neighbourhoods that vibrate at the grid’s frequency and inject higher line-frequency harmonics.
* Here LessLoss added that "you may want to mention other sources of invasive noise where the power company uses the power grid itself as a communication channel to monitor the health of and give direction to the entire system, adding yet more high frequency noise to the line. Also there are more and more systems in place which utilize the power grid's existing wires themselves for Internet communications."
Now enter the phenomenon known as the cable skin effect. This happens in all wires and cables. At DC a signal uses the entire conductor. The same amount of current flows in the center of each wire as does on the outside of the wire. Once the signal changes frequency as it does in a noise-polluted AC wave, a very odd effect occurs. The signal begins to move more to the outside of the conductor and gradually leaves the inside or center altogether. The higher the frequency, the more current bunching occurs on the outside of the conductor. For audio frequencies up to 20kHz the skin effect is almost negligible. Most the signal runs nicely ‘through’ the core. It’s once we consider MHz and GHz signals that the use of a hollow tube would be better suited. That would mean lots of skin and no core. It’s no wonder that we find copper-clad steel wiring in high-frequency environments. These wires remain sufficiently flexible and because only the outer layer of the conductor is of interest, cheap steel can form the core.
So there’s the unwanted noise—everything except for the 50 or 60Hz we need—which with rising frequency accumulates on the very outside of the conductors. If there was a way to use this skin effect as a filter, the resultant signal in the core should be what interests us. Naturally this isn’t a new idea. Exploiting the skin effect with special coatings goes back to the 1950s and 60s when televisions and radios were hot new domestic household items. The automotive industry then made many efforts to apply noise reduction for car and motorcycle ignition system wires, especially the wires between the distributor and spark plugs. All manner of inventions came about where a kind of lossy material got applied to the conductor. Metal mesh with very high resistance and thus ultra-fine wires or carbon powder mixed in a rubber coating were applied to these wires albeit not always with lasting effects. Many times a car or motorcycle could be ‘seen’ on TV or heard on the radio long before it would physically pass by. To exploit skin effect for effective filtering purposes relies on dealing with the following:
1. Frequency:skin effect increases with rising frequency. 2. Diameter: skin effect increases with larger conductor diameters. 3. Wire geometry: skin effect is lower for stranded bunches and higher for solid conductors. 4: Makeup: skin effect differs for different conductive materials. [Here Arkana Research’s use of rare earth metals comes into play which as raw materials exhibit very different properties from conventional copper or silver – Ed.]
LessLoss took these rules to heart and developed a unique porous material that acts like a maze for parasitic frequencies to get lost in. In their recent literature LessLoss no longer talk about porous materials but instead about pigments impregnated on the wire. For the current review subject, the range-topping DFPC Reference, the description is no clearer. The cable is said to undergo "several more crucial steps in processing and assembly" and "half a month of controlled steps in production" plus "12 hours of scrupulous labour for assembly". Here one should be in awe over such monk-like dedication. All we really know is that Louis Motek uses an inverted skin effect to attenuate high-frequency noise. The amount of attenuation increases with the cable’s grade level and the Reference series sports the highest: grade 4.**
** Here LessLoss added that "we understand this to critique us for not revealing more of the specifics of processes involved in production but I'd point out that it also sounds like a criticism of inconsistency, i.e. LessLoss is changing its story again and again. This is definitely not the case. We consistently describe the different skin-filtering levels but exact methods and procedures remain proprietary."
