faulty microfilter


Standard Member
I think I have a faulty microfilter and I need to work out if it is fixable. I have a standard BT line with an ethernet going out to one microfilter. This filter is separating telephone services and broadband. This microfilter is fine. The telephone cable coming out of the first microfilter, goes into a second that separates my landline telephone and two Sky box telephone line feeds.

My phone line works fine as if I plug the phone into the first microfilter, there is no problem. But if it's plugged into the second, there appears to be a problem and both my Sky boxes appear to be complaining about no phone line. So I'm assuming it is the second microfilter that has a problem, but it's surprising as I think it is less than 12 months old.

The main problem however is the second microfilter has the two Sky boxes hardwired in and not clicked in via an ethernet. So I was just wondering how is the best way to replace it? Should I just ask Sky to send someone or something out? Is it easier to just re-wire it myself and try and break into the faulty microfilter to suss the connection out (in case it is different to just a normal microfilter) or just cut the sky tv wire, wire it into an ethernet plug and then plug that into a new microfilter? :confused:


Active Member
The sky box plugs into the phone side of a microfilter.
The second connection should be into a phone splitter,not a microfilter.


Well-known Member
The diagram for "Connecting with a complicated layout" is incorrect. It shows a fax machine and satellite TV Box connected to a splitter then to a microfilter. Each unit should be connected to its individual microfilter and then to a splitter. If you connect them as shown in the diagram, it *might* work OK but it might result in problems or intermittent faulty operation.

Stevenage Neil

Distinguished Member
Simplistically a broadband enabled telephone line carries two signals. One broadband and two, all other telephone signals - phone, fax, Sky box etc.

Connect the microfilter at the master socket then the broadband modem/router connects to the ADSL port and everything else, phones, faxes, Sky boxes etc, to the "phone" connection via splitters or whatever.


Well-known Member
You can do that but it has to be an "active" filter. An ordinary microfilter can't cope with more than one device connected because the reduced impedance causes the crossover frequency to change away from the optimum. You can buy a special "master jack" socket which incorporates a filter.

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