[Gllug] ADSL problem

[Dylan]

On Sunday 27 Feb 2005 22:26 pm, Chris Bell wrote:
> 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.

Well, the whole line from the pole had to be replaced soon after, along 
with all the boxes in the house, when an ISDN was installed, and the 
engineer (I use the term advisedly, as he was a true old-time, once GPO 
guy) said the wiring was "flakey". I think he was using the term in its 
technical sense! :)

Dylan

>
>
> --
> Chris Bell

-- 
"I see your Schwartz is as big as mine" 
                                  -Dark Helmet
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