ADSL microfilters

[jim_in_sussex]

Hooray! Broadband has arrived! Am being told that every telephone must run through a microfilter at its socket.

Telephone cables here branch and daisy-chain all over the house, so that could cost a fortune.

Is this correct?

What I would like to do is to plug one of these filters in at the front door tel cable entry point & run a CAT5/wireless router system off the broadband point & feed the rest of the house telephone cabling off the telephone half of the microfilter.

ie is the microfilter a 'splitter' or does it just split off the broadband & leave the full signal going through the telephone output?

[Mike]

If you want to run lots of phones from the single filter it is best to get a proper splitter rather than a microfilter as the microfilter's characteristics change more as you add phones. You've a better chance of getting the full upstream data rate that way. While you're at it you could get an NTE5 installed.

[JoeJoe]

Even if you'll end up buying a MF per socket this should hardly cost you a furtune, unless you plan to give your business to Dixons or it affiliated...

See for example

(I've always used the cheapest ones, and never had a problem)

[Adrian Chapman]

Actually the adsl side passes straight through the splitter, it is the phone side is filtered. This is why you need a filter in every phone socket unless you install a BT style adsl faceplate. These can be bought from a number of places such as

[Martin Angove]

I have a replacement bottom half for a standard BT master socket. There are two sockets on the front; ADSL and telephone, and the extension IDC connectors on the back are telephone filtered so all extensions are covered by just this one filter. Cost about £12 from CPC IIRC so only worthwhile if you've more than 3 or 4 extensions and/or prefer the aesthetics.

Hwyl!

M.

[<me9]

That would be an excellent solution. They are a splitter. However, if the modem is not near the telephone entry point, it may be more economical to use more than one filter.

[John Rumm]

Not quite. Each phone (or phone type device including fax, analogue modem etc) needs to be filtered, but several devices can be served by one filter.

Yup easy enough. If you have a NTE5 master socket then the face plate splitter is the neatest solution.

Other way round - the broadband signal is the "full signal". The voice is the filtered part. (the filter is more to stop DC switching on the voice side (i.e. going on or off hook) messing with the broadband service than it is to stop the broadband from affecting the voice service (which 9/10 phones will simply ignore)

All the various types are available here:

[Set Square]

I'm not sure what you're referring to as the front door telephone cable entry point. If this is an NTE5 - fine. If it's just a junction box, you need to trace the wiring to the master socket, and operate on that. You're not supposed to touch anything on the BT side of the master.

Assuming that there *is* an NTE5 master socket somewhere with removeable faceplate, by far the best solution is to replace the faceplate with a modified ADSL one from Clarity.

has a filtered phone socket and an unfiltered ADSL socket on the front - and it *also* has IDC connectors for both filtered and unfiltered connections on the back. You can connect all your telephone wiring to the filtered connections - avoiding the need for any plug-in filters. You can run a CAT5 cable (although you one need one of its pairs) from the unfiltered connection to an RJ11/45 socket at a convenient location to plug in your ADSL kit.

Not only is this neater that any other solution, it is also technically superior and carries a much reduced risk of having your DIY telephone extension wiring interfere with the ADSL signal.

[mark_yh]

For what it's worth, when I ran without a microfilter for a short time the only effect I noticed was the total loss of caller ID on the phone.

[AnthB]

At GBP 1.50 (Inc VAT) at somewhere like ebuyer it's hardly going to cost a fortune is it?

[Joe Smith]

What sort of price is one of these?

[fred]

see 'shop' top right

[doozer]

I think you were probably quite lucky then. I've diagnosed a "faults" with ADSL for friends and family and it has invariably been a dead or missing microfilter. The symptoms in every case have been a dropped ADSL link whenever the phone is used. Perhaps you didn't notice that the ADSL went down when you were on the phone. After all if you aren't a heavy user you might never have used the ADSL and phone at the same time.

[John Rumm]

These modified filters are a good idea, although I have found you can achieve the same effect almost as neatly on a convetional BT style filter using a short RJ11 lead plugged into the unfiltered face socket, and then its tail looped into the back box of the NTE5 where you crimp it onto your CAT5 that runs to your remote unfiltered location.

[fredbloggstwo]

I would strongly recommend that you use a faceplate splitter on the master socket. It is much neater than using microfilters and I have also found that it makes a difference to the noise level on the ADSL side, which allows me to get a higher speed (I use UK online who use an adaptive technique that drives the line as fast as it will go without errors).

Kind regards, Mike

[Tim..]

I agree.

My set up is Split BT mastersocket and thence a loop to the fax machine point in the office, and then all other extensions after this.

Initially I had the Netgear supplied Microfilter plugged in with all the extensions plugged into it at the fax point and the modem unsatisfactorally sat on the window sill next to said fax machine.

I was getting a 512 connection with BT which would occasionally drop (though not when any phones were used).

I eventually found the time to resite the modem in my comms cabinet (under the stairs) using one of Clarity's NTE5 faceplates and running Cat5 from here to the comms cab (about 8 meters).

Since then i've not lost the connection once and my speed has jumped to a

1meg connection. I rang BT and asked if something had happened and they told me I was on a 1meg line all along.

So, it does make a difference!

Throw them dangly microfilters away!!

Tim..

[Mike Clarke]

I went for the faceplate option and got the XTF faceplate from ADSL Nation. I felt it was probably better value to spend 10.50 on just one good filter than to buy lots of "cheap" splitters.

I just fed this as the first extension from the NTE5 then connected the existing extension wiring to the filtered terminals on the back of the filter. The NTE5 is in installed in the loft so the lack of a filtered socket on that is no problem for us.

A point to watch with the ADSL Nation XTF is that the terminal numbers on the back refer to the BS pin numbers on the phone plug and not the BT numbering used on the PCBs of most sockets, i.e. 123456 becomes 654321. I should have noticed when I saw the bell line marked as 4 instead of 3 but I was just in painting by numbers mode and connected up the "correct" colours for the numbers with the result that the bells wouldn't ring on the extensions. Connecting 2,4 and 5 as though they were 5,3 and 2 sorted the problem. As far as I can see from the photos on their website this only applies to the XTF and not the NTF model.

[Peter Crosland]

That is often the problem. People will use cheap, and very nasty, filters that just don't do the job. As others have said buy a faceplate and do the job properly.

Peter Crosland

[Dave Plowman (News)]

You can get a master socket which splits the ADSL and phone line. That, of course, involves situating a router or ADSL modem fed from that somewhere then running CAT 5 etc to the computer. This is what I did in my cellar. Added one of these where the phone line came in and went to internal wiring. Changed the existing master to a slave. Situated a router close to this master and ran CAT 5 to the areas I needed it in.

TLC are a good source of modular outlets where you can mix RG45 and telephone sockets to your requirements. I used a four way RG45 in the cellar to convert to CAT 5 from the router, then replaced the existing telephone sockets where needed with an RG45 and BT outlet, which fit a one gang box. The master socket which includes a filter came from CPC.

Other way around. It removes the ADSL carrier from the phone line after it.

[John Rumm]

Not only that, you ought not have more than about 4 filters on the same line anyway to stay within the ADSL spec.

(Nothing to do with REN BTW)