curious wrote:




Only the phones need to have filters. The broadband modem doesn't need
one and it can cause problems if one is fitted or so I hear.

Bob

Not quite true (as kraftee says later)
The 'modem' side of a filter should (on decent units)have additional
components in it to isolate/protect the modem from the DC on the line,
the 25c/s ringing voltage and the dc changes caused by lifting/replacing
the handset on other phones.

Mike