Topband: ADSL router EMC problems

[Alan Ibbetson]

I recently upgraded to a broadband internet service using ADSL over the
phone line. I have an ethernet router/modem (Origo ASR 8400). I have no
problem with 7MHz and up, or on a dummy load, but when I transmit 400W
on 3.5 and only 100W on 1.8MHz the ADSL connection resets. 

Following the advice of my local EMC 'experts' I imported a pack of FT-
240-77 cores from the US and wound "lots" (8 or more) of turns of every
one of the cables going into the modem through cores. They make
absolutely no difference to the transmitter power level at which the
ADSL connection drops out.

Does this mean that the unwanted RF is arriving by some route other than
common-mode on the wiring to the router? Although I'm interested in
explanations, I'm more interested in suggestions as to what else I
should try. I realise that the details of DSL services will vary from
country to country but I'm hoping that others have experience of single
box consumer electronics that refused to respond to chokes on every wire
going into the box.

This is probably not of general interest to the group, so direct replies
would seem most appropriate. Thanks for your help.

Cheers,

Alan G3XAQ