What is a microfilter?
When your broadband is activated, your existing analogue telephone service will continue to work (and you can make voice calls as normal) with broadband operating at the same time. The ‘data’ signal and the regular voice signal are carried down the same line, each operating in a different part of the ‘spectrum’ (a bit like different radio stations). In order for the broadband signal not to interfere with your regular telephones, fax machines and answering machines, you will need a micro filter or splitter. The micro filter ‘strips out’ the high frequency data signal so that your phones receive the normal voice signal without interference.
This is a small electronic device that separates out a voice signal and a data signal on a single copper circuit. It plugs into the telephone socket on the wall and, itself, has two sockets, one for a phone or fax, the other for a computer or router. Every extension connected to the same copper circuit enabled with ADSL requires a separate microfilter. Care has to be taken that equipment plugged into the phone socket is compatible. ADSL is known to interfere with the operation of a number of telephone-based systems including, but not limited to; PBXs, credit card machines and alarm systems.
A microfilter allows two separate signals to be transmitted down your phone line: a low frequency analogue voice signal and a high frequency digital broadband signal. Without a microfilter in place the two signals will interfere with each other. You will need to install a microfilter in every phone socket that is in use, not just the one that your router is connected to. More information about microfilters is available here.
