DIY DSL Z-Filter

[DragonMaster]

I'd like to DIY-build a DSL Z-filter that should have enough current to be plugged in the phone box outside the house since I will have a dedicated phone wire when I'll install DSL(And I don't want to pay 5$/filter).

[dangus]

Why is that necessary? I really doubt that there'd be any problem running all the phones in the house through a single normal filter, assuming there is some convenient location to install it.

[Da5id4Vz]

I’ve done it both ways.

Works OK either way.

I’ve found it usually not too tough to get a service tech to install the NID mounted splitter as part of a service call.

[DragonMaster]

It's just that with the number of phones we have, + if we want to add one, every time, it makes a 5$ more, and the NIDs are screwed to the 1' high balcony so it's easy to install.

[Da5id4Vz]

Try stuffing as micro-filter in the NID. You need of course to run line directly to the ADSl modem.

I did it this way for a couple of years. I suspect the noise floore on the POTS may have been a bit hight than if using an LPF-200, but it was sitll very usable.

[DragonMaster]

Oh, so I can cut the plug of a standard crappy filter and use it? I thought it needed a heavier duty filter, to hold 5 or + phones.

[Da5id4Vz]

A lot of, but not all, of the difference has to do with form factor and weatherization.

I think you should try to keep the filter as standard as possible. It just makes it easier if you have to do troubleshooting. When I did mine, I home ran all the phones to one spot. It made it easy to patch the microfilter into a block of phone lines and leave one free for the modem.

These things are really just low pass filters deigned to cut the DMT carriers out of the telephones audio band. They also keep the phones from crunching the DMT when the phones are on hook.

I dont think 5 phones on one microfilter should be a big issue. You might here some a little hash in the background. Id have a tough time telling whether the NID filter was quieter than the microfilter. At the time I lived near a radio station and was getting enough audio modulated into the handset cords it was tuff to tell.

[DragonMaster]

The NID filter filters the DSL line too, with an high pass filter so the voice doesn't produce ringing in the signal(So the DSL doesn't slow down when phone is used)

[DragonMaster]

Yay, the lines are all going to the same point(In the house). I'll just stick a filter there.

[DragonMaster]

Well, there's still a phone where I hear the noise. It's pretty quiet tho. That same phone is connected in an other phone that doesn't show this problem.