Noisy ADSL BT Line

I've just installed a netgear ADSL router box at my inlaws so that they have a reasonable speed connection to the internet.

I've noticed that their telephones are now very hissy - and yes, I've tried 2 types of Microfilter and neither seems to make any difference. If I turn the netgear box office the hiss disappears of course.

Can anyone make any suggestions that might reduce the hiss on the phone lines??? Otherwise, they'll be turning the netgear box on and off whenever they want to access the internet, email etc, which sort of negates the point of having an "always on" internet connection.

Thanks.

[mitchja]

Noisy lines when using ADSL is usually down to a micro-filter problem as the noise and hissing sound you hear is the ADSL signal.

What make of micro-filter are you using? Micro-filters do vary in quality. Some are better than others. A good one is one of these

Obvious question but have you made sure every BT socket has a micro-filter plugged into it? Every socket must be filtered in order to get your phone line and ADSL working properly. Even BT sockets with no phone plugged into them should really be filtered as well as the filters not only filter out the ADSL signal where it's not needed, they also terminate the ADSL signal to stop it from bouncing back up your line.

Netgear do usually give you one good quality micro-filter with their routers but you may need more than one for every socket. I have 4 sockets in my house, all with a micro-filter plugged into them. Also using a Netgear ADSL router here as well.

Regards

This is interesting as I don't believe all sockets have the filters on them - I assumed that they were only needed where a phone was plugged in.

Also, I saw a suggestion on a forum that it might be beneficial to "daisy-chain" 2 filters to get a better filtering effect. I'm not sure if that would work though?

Thanks for the input - other suggestions welcomed.

Something just occurred to me - when I turn off the ADSL netgear box the hissing goes away...???