Re: Electric Shock!
All things electrical must comply with a number of EU directives to qualify for their CE mark. The EMC directive requires equipment not to radiate too much electromagnetic energy and also to be unaffected by radiation from elsewhere.
To meet the EMC directive most things need filters in their circuits. What you are seeing is a ferrite clamp, so just a chunk of ferrite material around the cable - this forms a common-mode choke which helps to make the cable a less-good aerial. Ferrite clamps are expensive so they typically get used when a design that was expected to pass the tests actually just failed. Adding a ferrite clamp is a quick way to get a few extra dB improvement.
At least they were trying!
|