I finally got DSL out in the sticks here a couple of weeks ago, and of course
more than 100W killed my modem too. Winding the phone line round a toroid
helped a bit but not enough - the reasons for that are well known, but it's the
easy first thing to try! I then built a simple filter, the schematic of which
I got from G3PQA, but I believe it was an OK station who actually designed it.
(Apologies for lack of proper credit.) As I can't put a drawing on here, I will
attempt to describe it:
It is a balanced filter with two series inductors in each leg and parallel
capacitors at input, output and mid point. All four inductors are 6.51uH (I
used 6.8uH). The input and output capacitors are 4.53nF (I used parallel
2.2nF). The centre capacitor is 6.37nF (I used parallel 3.3nF).
I built it in a telephone connection box which gave me 8 places to fix
components - no pcb. It works like a charm and I can't detect any difference in
connection speed with it in or out of circuit (~5M).
Hope that helps.
73 Roger
VE3ZI
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