To filter or not to filter, that is the question...

dahamsta

I have noise on my line and can't get rid of it. I had an Eircom engineer out to look at the problem (it only took six phone calls to the obnoxious curs in Eircom repairs) and he reckoned it was because my wiring that was at fault (this time UTV's fault, because they didn't book an engineer to remove the ISDN box).

Anyway, less of my bitching: While he was here, he told me that I don't need filters on every extension in the house. I brought him up on this, telling him that I'd checked several websites about it, and that they all recommended that each extension should have a filter, unless of course all the extensions come off the voice port on the main extension. Nope, he says, just the main one.

ADSLguide says he's wrong. Who's right?

adam

shinzon

the training i was given with the isp i work for for broadband, categorically stated that you need a filter for anything thats plugged into an extension socket throughout the house

if theres nothing plugged into it then you dont need a filter in it simple as that

shin

crowbar

the broadband signal is sent using a frequency range above that which is used by a normal phone, so unless your phone(s) have built-in filtering restricting it to receiving and transmitting on only the frequencies used for the phone, then they may well cause noise on your line and/or interfere with your adsl line.

maybe the engineer is talking about one of those filters that are built into the master wall plate, and has a dsl socket and a phone socket. if all your extension sockets are parallelled to the phone side of the wall plate, ie. after the filter, then you won't need filters on all your other sockets because the master plate has already done the filtering. basically this degenerates into the second scenario that adslguide describe, but using built-in cabling ... something like this:

                    [
line in --- filter -[-- dsl modem
               |    [
               \-*--[-- phone
                 |  [
                 |
                 =
                 |
                 |  [
                 \--[-- extension phone
                    [

P3nfold

Indeed. Every socket which is in a "in use" basis must be filtered. This also applys to other services such as sky digital, interactive alarm service ect..