Eliminating radio interference from Apple charger
>  This radio interference was also present on the aviation frequencies (around 124 MHz)<p>How did this thing get FCC approval? What's it's FCC approval number? Who tested this thing? Want to look that up.<p>If RF got outside the charger and into the USB cable, it's very badly designed. The power in the USB cable is DC. There shouldn't be any significant RF component. There should be ferrite beads and capacitors in the power supply to deal with this. When the filtering is close to the switcher, it's much easier to deal with the noise, and very small ferrite beads, available in surface mount, can usually do the job. Once it gets out on an external wire, it's hard to filter.<p>This is an old problem for Apple. A report from 2013, from a pilot charging an Ipad in an aircraft.[1]<p>[1] <a href="https://pointsforpilots.blogspot.com/2013/06/radio-interference-of-12v-ipad-charger.html" rel="nofollow noreferrer">https://pointsforpilots.blogspot.com/2013/06/radio-interfere...</a>