Svideo cables

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  [Deleted User] Posts: 3,527

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  27/03/06 - 09:45 #2

  I assume you mean a "bulb" thing just before the cable terminates to the connector?
  
  I dont know their technical name or exactly how they work but my understanding is that they are used to help reduce interferance - in a similiar way you can buy seperare collars to put on cables.
  
  Most s.video cables dont have these attached - if you are looking for a mid quality cable I would look at the brands QED and IXOS

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  [Deleted User] Posts: 4,458

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  27/03/06 - 09:51 #3

  Astaroth wrote:

  I assume you mean a "bulb" thing just before the cable terminates to the connector?
  
  I dont know their technical name or exactly how they work but my understanding is that they are used to help reduce interferance - in a similiar way you can buy seperare collars to put on cables.
  
  Most s.video cables dont have these attached - if you are looking for a mid quality cable I would look at the brands QED and IXOS

  
  Yes those jobbies just before the connector.
  
  I have 2 10m cables and they both have them. Is it anything to do with the length?
  
  I'll check out QED and IXOS, cheers.

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  [Deleted User] Posts: 3,527

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  27/03/06 - 16:02 #4

  I think you will find it is probably more a "brand" thing than a length. Having a quick search showed a couple of brands that seem to have them on almost all run lengths and others that didnt have them at 10m plus.

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  oldie Posts: 172

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  28/03/06 - 13:20 #5

  Simply put and without going into any great detail, as the whole subject is very complex, to conform to the CE Marking Directive, electrical apparatus needs to comply with the electromagnetic compatibility (EMC) regulations. In effect, this means that the apparatus should not emit, or be susceptible to, electromagnetic fields above a certain prescribed level. (Just about all electrical apparatus will radiate an electromagnetic field of some kind when it is functional).
  
  I know this statement is, of necessity, very simplified, and to learn more, I suggest the reader carries out an Internet search for, say, "EMC Regulations" or "Electromagnetic Compatibility". There is a huge amount of information out there, most of which is highly technical. Have fun!
  
  For a radiated emission test, apparatus is tested with cables of a specified length attached to its terminations. E.g., say, 3 metres of S-video cable connected to an S-video output socket on a VCR. A very sensitive, special type of radio receiver with attached antenna is aimed at the apparatus under test in order to measure the amount of Radio Frequency radiation.
  
  From my own experience, the amount of radiation can be proportional to the length of attached cable.
  
  In order to limit the radiation from the cable, a ferrite (type of magnetic material) ring is added adjacent to the cable plug. There may be one at each end so it does not matter which way round the cable is fitted. The ferrite ring is either an unbroken ring or may be split into two and the two halves clamped tightly together.
  
  The ring has the effect of reducing the amount of electromagnetic signal which is being produced inside the VCR from being radiated by the cable. It may also help to reduce the electromagnetic signal being picked up by the cable from other sources from being introduced into the VCR.
  
  In general, if apparatus is supplied with cables with ferrite rings attached, it is because the accompanying apparatus didn't comply with the regulations without them, so it is always recommended that the supplied cables should be used.

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