[ALUG] OT: ADSL T-Bar?

[Wayne Stallwood]

Mark Rogers wrote:
> Chris G wrote:
>> It's a BT "line improver" isn't it?  I seem to remember it being
>> greeted with some skepticism by gurus but that they changed their
>> minds and that it really *does* improve speed quite often.
>>
>> Here you go:-
>>
>>     
>> http://www.productsandservices.bt.com/consumerProducts/displayTopic.do?topicId=25075 
>>
>>
>> "BT Broadband Accelerator" is BT's new name for the I-Plate
>
> I know a little about I-Plate (ie that it exists); but the customer 
> was quite clear about this "T-Bar" thing and I've never heard the 
> I-Plate called by that name. (As I understand it, the I-Plate just 
> disconnects the ring capacitor doesn't it?)
Sort of,

the i-plate disconnects the ring wire which is wired from the master 
sockets ring capacitor to other slave extensions in the house and I 
think it may also provide some additional filtering. The ring wire is a 
legacy thing from the days of REN numbers on phones where an additional 
ring voltage was needed to power the ring sounders in phones (back from 
them being a bell but some "electronic" ringers needed it too). This 
wire is redundant on modern telephones and therefore acts as a open 
ended pickup collecting EMI from other things in the house (and from the 
line itself) adding noise to the line.

As Nev states, simply cutting the wire at all sockets will have the same 
effect but the i-plate is a consumer friendly way of achieving much the 
same thing without having to resort to the wire snips (and the resultant 
support and engineer visits if "ordinary" people were asked to do this)*

However still the optimum way to operate ADSL is to filter off the ADSL 
with the original BT splitter faceplate at the master socket and run a 
separate (ADSL only) pair up to your modem/router. So those that had the 
original BT engineer installation ADSL service will already have the 
masterplate splitter as this is how the first ADSL installations were 
performed in the UK. People like me with this setup will have nothing to 
gain from the i-plate.

Effects of doing this are quite varied and dependent on the state/volume 
of extension wiring in the house and the quality of the ADSL service to 
begin with, I have been cutting that wire as a matter of course for 
several years now and have seen everything from no effect at all to ADSL 
that wouldn't even sync without this being done.

* Disclaimer AFAIK the situation is still that you aren't supposed to do 
this on the master socket yourself, but I don't think there is any 
penalty beyond getting charged for a call out should you introduce a fault.