[Gllug] ADSL problem

[Chris Bell]

On Sun 27 Feb, Dylan wrote:
> 

> 
> That sounds very much like you need a replacement microfilter - we had a 
> lightening strike here last summer which blew out a microfilter 
> (literally, bits of it melted on the wall) and had exactly the same 
> problem on phonecalls until it was replaced. Luckily, because the 
> filter blew up, the surge didn't hit the ADSL router and enter the 
> network!
> 
   There should be (or should have been) a spark gap between the incoming
wires, hidden inside the BT master box, and much computer comms equipment
now has an opto-isolator on the input. If you are in an area prone to
lightning strikes you can feed the incoming pair through a ferrite core a
few times, (an old TV line output transformer core would be ideal), or get a
rather more beefy metal cased protector with a good earth connector (more
expensive, but claimed to work well).
   I have been told that telephone boxes often sustained lightning strikes,
and there was often very little damage visible, just a pair of holes in the
cable outer where the spark jumped a bend in the cable.


-- 
Chris Bell

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