No ring without filter

I recently fitted an ADSL Nation filtered faceplate, so everything has improved. However, having established here that I don't need filters at extensions, I removed the filter where it was used at the BT hardwired extension. (BTW when I fitted the filtered faceplate at the master, I remade the extension wiring to the same numbered terminals on the new faceplate as in the original). I thought the extension was ok (it was certainly quieter since the new faceplate) since removing the filter the phone no longer rings. Put the filter back in and it does ring!! The phone is an old pulse dial one which used to ring just fine before fitting the filtered faceplate. The phone is fine with filter, but I'm just mystified.
Any ideas please?

Edit: BTW it's this type of filter.

Edited by rob54 (Sat 11-Aug-12 20:49:57)

When fitting the extension did you disconnect the ring wire? The older phone may need it. Filters have a capacitor in them that enables the phone to ring even if the ring wire is disconnected.

Following on from what Kr1s69 says, it is fine with the ADSL Nation XTE-2005 to connect the ring wire on T3 at each end. That's assuming you are using T2 and T5 for the extension, not the unfiltered extension A/B.

It incorporates a filter on T3.

If you are using the unfiltered A and B, then you need the extension filter anyway.

Edited by RobertoS (Sat 11-Aug-12 21:36:02)

There were three wires connected to the back of the original master faceplate as here and I connected those three to the only three numbered terminals behind the ADSL Nation faceplate. So AFAIK the answer is no.
But OK that explains why the phone rings with the filter. Maybe the ring wire connection is not good. I used a, eerm is it Krone tool, a disposable one, I bought with the faceplate.

We'll probably do away with the old phone soon so it won't matter so much.

Edited by rob54 (Sat 11-Aug-12 22:45:11)

Is the ring wire connected at the extension?

Nothing wrong with the cheapo Krone tools.

In reply to a post by RobertoS:

...If you are using the unfiltered A and B...

Irrelevant to the OP but A and B supply an unfiltered ADSL signal - does that carry the voice frequencies also? If it does, is that A-B connection OK to use for a router without filtering off the voice frequencies?

Often wondered about that with the A-B connections at the back of filtered faceplates

In reply to a post by 4M2:

Irrelevant to the OP but A and B supply an unfiltered ADSL signal - does that carry the voice frequencies also? If it does, is that A-B connection OK to use for a router without filtering off the voice frequencies?

Often wondered about that with the A-B connections at the back of filtered faceplates

The thing is, you have the opposite idea of what ADSL filters do to what is in fact the case. (Ignore the T3 ring wire as irrelevant for this discussion).

The ADSL/VDSL2 filter removes the broadband signals from the telephone connections. Not the phone signals from the broadband connection. If it didn't, you wouldn't be able to hear a darn thing on the phone. Ever heard a dialup modem connecting? Or picked up a ringing phone and just heard a high whistle? That is a modem (probably a fax) trying to connect.

Neither does a conventional filter split the two signals. It could only do that by containing two filters, one to remove broadband, feeding the phone socket, followed by another removing the phone stuff. So more than doubling the complexity of the bit of kit.

ADSL/VDSL2 sockets present everything that is on the line to whatever is plugged into them. Filtered phone sockets only get analogue audio frequencies. A modem or modem/router on a ADSL/VDSL2 filtered socket gets an unfiltered signal, including the phone frequencies which it ignores.

So the A/B connectors on the back of filtered faceplated get a completely raw signal, effectively direct from the main incoming Openreach line. Straight through - hidden main A/B >> test socket >> faceplate >> extension A/B supply.

Anything on the extension at the other end requires a filter.

Except!!!

In an installation where absolutely nothing is connected to the phone line except a modem or modem/router, no filters are needed at all. (Though if physical extensions are present but not used, their ring wires may need removing or filtering. I believe some early filtered faceplates did not filter it. It's the ring wire's capability of picking up and feeding back random electromagnetic noise that is the problem).

Edited by RobertoS (Sun 12-Aug-12 00:05:59)

Thanks Bob - as always your replies are thorough and highly informative

I think my misconception was based on the use of the term "filter/splitter" where I assumed the actual signal was split into broadband and analogue audio frequencies as two separate entities. The fact that an adsl modem/router can ignore phone frequencies means that it can be connected directly into the test socket with a telephone plug to rj11 modem lead, if I understand you correctly, and thus not require a filter which I always thought was necessary.

In reply to a post by 4M2:

The fact that an adsl modem/router can ignore phone frequencies means that it can be connected directly into the test socket with a telephone plug to rj11 modem lead, if I understand you correctly, and thus not require a filter. (which I always thought was necessary).

Correct .

For some reason I had the impression that the A-B connections on the back of a filtered faceplate were exclusively for adsl but now you have shown that they can in fact be used for an extension where both voice and broadband are required, a filter obviously being needed due to the raw signal.

Also ,as you pointed out to the OP, a bell wire could not be used if connecting an extension to A-B since only two wires are in use....interesting stuff, many thanks for the clarification