D-Link DSL-502T User Manual - Microfilters and Splitters

DSL-502T ADSL Router User’s Guide 

D 

Microfilters and Splitters 

Most ADSL clients will be required to install a simple device that prevents the ADSL line from interfering with 

regular telephone services. These devices are commonly referred to as microfilters or sometimes called 

(inaccurately) line splitters. They are easy to install and use standard telephone connectors and cable. 

Some ADSL service providers will send a telecommunications technician to modify the telephone line, usually 

at the point where the telephone line enters the building. If a technician has divided or split your telephone line 

into two separate lines - one for regular telephone service and the other for ADSL – then you do not need to use 

any type of filter device. Follow the instructions given to you by your ADSL service provider about where and 

how you should connect the Modem to the ADSL line. 

Microfilters 

Unless you are instructed to use a “line splitter” (see below), it will be necessary to install a microfilter (low pass 

filter) device for each telephone or telephone device (answering machines, Faxes etc.) that share the line with the 

ADSL service. Microfilters are easy-to-install, in-line devices, which attach to the telephone cable between the 

telephone and wall jack. Microfilters that install behind the wall plate are also available. A typical in-line 

microfilter installation is shown in the diagram below.  

Microfilter Installation 

Important: Do not install the microfilter between the Modem and the telephone jack. Microfilters are only 

intended for use with regular telephones, Fax machines and other regular telephone devices. 

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