On Mon, 26 Mar 2007 09:04:43 +0100, Dave Plowman (News) wrote:

The filter(s) is/are to stop the ADSL carrier interfering with the
phones - not the other way round.

ADSL carriers, plural. Upstream starts near 25 KHz up to around 138 kHz
and the downstream from there right up to about 1.1MHz in 4 kHz (or there
abouts) steps. This is for the now common 8 Mbps service. The 24 Mbps
service doubles the top frequency to 2.2 MHz. Which is why it doesn't work
any better than the 8 Mbps service once the local loop is about a mile
long.

The filter is to stop phones shunting the low level RF carriers rather
than them interfering with the POTS.

--
Cheers
Dave. pam is missing e-mail