"Pete C" wrote in message
...
On Wed, 28 Apr 2004 21:44:32 GMT, Ian Stirling
wrote:

For short/quiet lines, it generally works fine, even with no filters.
Slightly longer, and the ADSL may cut out when a phone is picked up.
Longer than this, and it requires filters to work at all.

Tried it on mine this afternoon, works OK until you pick the phone up

I suppose the phone can also generate signals in the ADSL
frequencies which interfere with it.

No it can't. The filter is there to isolate the high frequency ADSL signal
from the rectifying effects of the non-linearities in the phone which would
give rise to all sorts of noise. Some phones have non-linearities in the
ringers when on-hook so these won't work at all, whereas others are fine
until you go off-hook. There was a concept in 1998 called ADSL-lite which
depended on this but it died the death that all crap ideas should.