Fax machine at home - with one phone line ?

[johnc]

Most (all?) fax machines can be set to not answer or to answer after a maximum number of rings (in the case of a prehistoric Murata thermal unit I'm still using, that number is seven)--if the latter, set the answering machine to answer after a shorter duration (number of rings). The fax machine will silently "listen" for transmission tones (whether you pick up the handset or the answering machine answers). If those tones are detected, it will disconnect the handset (or answering machine) and receive the incoming fax.