Completed my CAT 5 terminations (T568B) and my Clarity modified
Microfilters & NTE5's have arrived.

Intend following advice given here (Peter Parry amongst others) to
patch across only 2 & 5 from the filtered side of the NTE5 to the CAT5
patch panels, and then use PABX master LAU at each faceplate outlet
where I want phones.

This is to avoid any issue with the Microfilter not providing enough
REN - each LAU having it's own capacitor.

To achieve this I have a number of CAT 5 ways on one of the patch
panels 'paralled' so as long as I plug my filtered POTS feed into one
'way' I can patch out from the other 'paralled' ways to any of the
outgoing 'ways' on normal panels to room outlets.

I could play about until it works, but does anybody know what
connections on a RJ45 plug I need to connect the POTS ?

The LAU's show that it has phone across 2 and 5 of the BT socket
(normal) and these connect to pins 5 & 4 respectively on the RJ45
plug.
The capacitor is connected across pins 5 & 4 of the BT socket.

This is the bit where it is slightly confusing as the capacitor is
normally across 2 & 3 ?


So does that mean standard phones with BT 431 plugs pre-wired will not
work ? as they will expect ringing on 3 and it will be on 4

In article . com,
Osprey wrote:
This is to avoid any issue with the Microfilter not providing enough
REN - each LAU having it's own capacitor.

I've got one filter where the line comes in. Goes to my router and normal
telephone wiring. I've got 8 phones and they all ring. They consist of
four ordinary phones and 3 cordless base stations.

--
*If your feet smell and your nose runs, you're built upside down.

Dave Plowman London SW
To e-mail, change noise into sound.

On 23 Feb 2007 16:02:44 -0800, "Osprey"
mused:

Completed my CAT 5 terminations (T568B) and my Clarity modified
Microfilters & NTE5's have arrived.

Intend following advice given here (Peter Parry amongst others) to
patch across only 2 & 5 from the filtered side of the NTE5 to the CAT5
patch panels, and then use PABX master LAU at each faceplate outlet
where I want phones.

This is to avoid any issue with the Microfilter not providing enough
REN - each LAU having it's own capacitor.

Not quite, REN is the amount of line current available to drive the
ringer circuit. Doesn't matter how you wire your phones, the REN is
the same.

Think of REN as like your main fuse by the electric meter and the
phones like electrical appliances.

To achieve this I have a number of CAT 5 ways on one of the patch
panels 'paralled' so as long as I plug my filtered POTS feed into one
'way' I can patch out from the other 'paralled' ways to any of the
outgoing 'ways' on normal panels to room outlets.

I could play about until it works, but does anybody know what
connections on a RJ45 plug I need to connect the POTS ?

Pins 4 & 5 (blue pair on 568B wiring). Why do you need to connect any
RJ45 plugs up though, just use a standard patch cable between the
voice port and data port on the patch panel and plug the LAU into the
data outlet.

The LAU's show that it has phone across 2 and 5 of the BT socket
(normal) and these connect to pins 5 & 4 respectively on the RJ45
plug.
The capacitor is connected across pins 5 & 4 of the BT socket.

This is the bit where it is slightly confusing as the capacitor is
normally across 2 & 3 ?

I'd imagine the 'capacitor' is in fact a surge arrestor as these are
the only things normally fitted across 2 & 5.

So does that mean standard phones with BT 431 plugs pre-wired will not
work ? as they will expect ringing on 3 and it will be on 4

Just plug one in, it'll work or it won't.
--
Regards,
Stuart.

On 24 Feb, 03:02, Lurch wrote:
On 23 Feb 2007 16:02:44 -0800
mused:

Completed my CAT 5 terminations (T568B) and my Clarity modified
Microfilters & NTE5's have arrived.

Intend following advice given here (Peter Parry amongst others) to

Not quite, REN is the amount of line current available to drive the
ringer circuit. Doesn't matter how you wire your phones, the REN is
the same.

Think of REN as like your main fuse by the electric meter and the
phones like electrical appliances.

snip
Pins 4 & 5 (blue pair on 568B wiring). Why do you need to connect any
RJ45 plugs up though, just use a standard patch cable between the
voice port and data port on the patch panel and plug the LAU into the
data outlet.

I'd imagine the 'capacitor' is in fact a surge arrestor as these are
the only things normally fitted across 2 & 5.


No 100% certain it's the ringing capacitor.

You may have misunderstood - I'll try again.

The advice I had (from many here & on Automated home) was to parallel
a number of ways on the back of a patch panel .... then by feeding a
single POTS feed into the front of this 'paralleled' set ... a patch
lead from any other socket on this set will distribute the POTS to the
outgoing patch panel sockets.

perhaps this drawing will explain: http://tinyurl.com/2lnr9m

This allows me to patch in or out phones to the 'paralleled ways' as I
want.

Which may be what you describe as " just use a standard patch cable
between the
voice port and data port on the patch panel and plug the LAU into the
data outlet."

The advice given by several people was that while REN is limited by
the AC current sent by the ringing generator in the BT exchange - it
is affected by being fed by via one ringing capacitor if a single
microfilter is being used.

As I have RJ45 outlets in each room, an LAU is used, again the advice
here was to use PBX Master LAU.

These most definitely have phone across 2 & 5 and there is a
standard ringing capacitor across 4 &5 .. Here is the manufacturers
data sheet -
http://www.molexpn.co.uk/products/pdf/AAA.pdf


Will patch across 2 & 5 from NTE5, (to 4 & 5 on patch panels you
suggest) .. I am still unsure of the capacitor connection at LAU ...
it is across 4 &5 on the BT socket side ... and not sure how that is
going to work where a phone expects ringing across 3 & 5.

On 24 Feb 2007 03:23:38 -0800, "Osprey"
mused:

I'd imagine the 'capacitor' is in fact a surge arrestor as these are
the only things normally fitted across 2 & 5.


No 100% certain it's the ringing capacitor.

You may have misunderstood - I'll try again.

The advice I had (from many here & on Automated home) was to parallel
a number of ways on the back of a patch panel .... then by feeding a
single POTS feed into the front of this 'paralleled' set ... a patch
lead from any other socket on this set will distribute the POTS to the
outgoing patch panel sockets.

perhaps this drawing will explain: http://tinyurl.com/2lnr9m

This allows me to patch in or out phones to the 'paralleled ways' as I
want.

Which may be what you describe as " just use a standard patch cable
between the
voice port and data port on the patch panel and plug the LAU into the
data outlet."

Yeah, that's pretty much what I was getting at. I've got the same
setup at home, but rather thean pach the phone feed into the front
it's punched down on the back so the patch panel sockets are purely
outlets for distribution to data sockets.

The advice given by several people was that while REN is limited by
the AC current sent by the ringing generator in the BT exchange - it
is affected by being fed by via one ringing capacitor if a single
microfilter is being used.

Yes, think I see what you're getting at here.

As I have RJ45 outlets in each room, an LAU is used, again the advice
here was to use PBX Master LAU.

These most definitely have phone across 2 & 5 and there is a
standard ringing capacitor across 4 &5 .. Here is the manufacturers
data sheet -
http://www.molexpn.co.uk/products/pdf/AAA.pdf


Will patch across 2 & 5 from NTE5, (to 4 & 5 on patch panels you
suggest) .. I am still unsure of the capacitor connection at LAU ...
it is across 4 &5 on the BT socket side ... and not sure how that is
going to work where a phone expects ringing across 3 & 5.

It'll be fine, just plug it all in! If it's wrong, it won't work, if
it works then it saves me explaining why it will .

I think you may have counted something upside down somewhere which
could be causing confusion, like for instance on a BT431a pin1 goes to
pin6 in a BT socket.

Anyway, just plug it all in.
--
Regards,
Stuart.

Osprey wrote:

This is the bit where it is slightly confusing as the capacitor is
normally across 2 & 3 ?

Ah, well sort of - you have been caught out by a none to smart bit of
engineering.

As you rightly say the ring signal is presented to pin 3 on the plug of
your telephone. However in order to make connection to this wire on the
BT socket, you need to connect it to the pin labelled 4 on the socket.
This is because some bright spark numbered the pins in opposite
directions on plugs and sockets. So the correct assignments are pin1 on
socket goes to pin 6 on plug, 2-5 3-4 4-3 5-2 6-1

So does that mean standard phones with BT 431 plugs pre-wired will not
work ? as they will expect ringing on 3 and it will be on 4

Should all work out nicely in the end!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In an earlier contribution to this discussion,
Osprey wrote:

On 24 Feb, 03:02, Lurch wrote:
On 23 Feb 2007 16:02:44 -0800
mused:

Completed my CAT 5 terminations (T568B) and my Clarity modified
Microfilters & NTE5's have arrived.

Intend following advice given here (Peter Parry amongst others) to

Not quite, REN is the amount of line current available to drive the
ringer circuit. Doesn't matter how you wire your phones, the REN is
the same.

Think of REN as like your main fuse by the electric meter and the
phones like electrical appliances.

snip
Pins 4 & 5 (blue pair on 568B wiring). Why do you need to connect any
RJ45 plugs up though, just use a standard patch cable between the
voice port and data port on the patch panel and plug the LAU into the
data outlet.

I'd imagine the 'capacitor' is in fact a surge arrestor as these are
the only things normally fitted across 2 & 5.


No 100% certain it's the ringing capacitor.

You may have misunderstood - I'll try again.

The advice I had (from many here & on Automated home) was to parallel
a number of ways on the back of a patch panel .... then by feeding a
single POTS feed into the front of this 'paralleled' set ... a patch
lead from any other socket on this set will distribute the POTS to the
outgoing patch panel sockets.

perhaps this drawing will explain: http://tinyurl.com/2lnr9m

This allows me to patch in or out phones to the 'paralleled ways' as I
want.

Which may be what you describe as " just use a standard patch cable
between the
voice port and data port on the patch panel and plug the LAU into the
data outlet."

The advice given by several people was that while REN is limited by
the AC current sent by the ringing generator in the BT exchange - it
is affected by being fed by via one ringing capacitor if a single
microfilter is being used.

As I have RJ45 outlets in each room, an LAU is used, again the advice
here was to use PBX Master LAU.

These most definitely have phone across 2 & 5 and there is a
standard ringing capacitor across 4 &5 .. Here is the manufacturers
data sheet -
http://www.molexpn.co.uk/products/pdf/AAA.pdf


Will patch across 2 & 5 from NTE5, (to 4 & 5 on patch panels you
suggest) .. I am still unsure of the capacitor connection at LAU ...
it is across 4 &5 on the BT socket side ... and not sure how that is
going to work where a phone expects ringing across 3 & 5.

Be aware that there seem to be two alternative numbering systems in use for
the pins in BT modular plugs - counting from opposite ends!

The ringer capacitor in a BT master socket is connected between 2 and 3 in
one system. In the other system, this would equate to 5 and 4 - which is
what you appear to have with your LAUs. Chances are that they will work ok.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Roger Mills wrote:

Be aware that there seem to be two alternative numbering systems in use for
the pins in BT modular plugs - counting from opposite ends!

No, there's only one system, but it's true that the pin numbering of the
modular connector runs the opposite way to the terminal numbering of
the line jack units (LJUs). LJU terminal 1 goes to connector pin 6 and
so on. Connector pin 6 is the one nearest the springy latch/release
lever. People normally refer to the LJU terminal numbers unless talking
about the D-shaped cordage on the phone (CPE) side.

The ringer capacitor in a BT master socket is connected between 2 and 3 in
one system.

A master LJU has a 1.8 uF cap between terminals 2 & 3 (corresponding to
pins 4& 5 on the connector side). Terminal 2 should be the B-wire of
the line (at about -50 V to earth when all phones are on-hook).

In the other system, this would equate to 5 and 4 - which is
what you appear to have with your LAUs. Chances are that they will work ok.

That sounds right then. Micro filters and LAUs tend to have a smaller
value capacitor, which is why they can only support a higher impedance
ringer load (lower REN number).

--
Andy

Andy Wade wrote:

That sounds right then. Micro filters and LAUs tend to have a smaller
value capacitor,


Is this to save space, or to allow for the fact that there will often be
several microfilters connected in parallel?

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 24 Feb 2007 03:23:38 -0800, Osprey wrote:

The advice given by several people was that while REN is limited by
the AC current sent by the ringing generator in the BT exchange - it
is affected by being fed by via one ringing capacitor if a single
microfilter is being used.

The single C in the master socket is how the POTS system should be
configured with the ringing line distributed to all extension sockets.

I'd be a litle concerned about all the additional C's in the LAUs
affecting the response of microfilter in some way and messing up your
ADSL. Remember that the POTS side is the filtered side not the ADSL which
is straight through.

There are also some reports that connecting the unbalanced ring line back
into the NTE filter is not a good idea as it injects noise and thus
reduces the ADSL performance. So there maybe a case for only bring 2 & 5
from the NTE to your patch panel but deriving the ring signal there with
a single, (proper sized) C for distribution.

--
Cheers
Dave. pam is missing e-mail

John Rumm wrote:
Andy Wade wrote:

That sounds right then. Micro filters and LAUs tend to have a smaller
value capacitor,

Is this to save space, or to allow for the fact that there will often be
several microfilters connected in parallel?

It will save space and cost, but I suspect the designer's viewpoint is
that the max. ringing load on the o/p of a filter will be a REN of 1
then the capacitor only needs to have a quarter of the value needed for
REN = 4, i.e. 470 nF would do.

Having said that I see that BT SIN346 says:

"Note that the standard BT PSTN CPE interface is a 3 wire circuit
whereby the bell wire is AC-coupled from line B. This bell wire must
either be filtered by the filter or left open circuit at the Line Port
and recreated at the Telephony Port of the filter. This is may be
achieved using a 1.8 µF capacitor between line B (pin 5) and the bell
wire (pin 4) at the Telephony Port."

--
Andy

On 25 Feb, 11:00, "Dave Liquorice" wrote:
On 24 Feb 2007 03:23:38 -0800, Osprey wrote:

The advice given by several people was that while REN is limited by
the AC current sent by the ringing generator in the BT exchange - it
is affected by being fed by via one ringing capacitor if a single
microfilter is being used.

The single C in the master socket is how the POTS system should be
configured with the ringing line distributed to all extension sockets.

I'd be a litle concerned about all the additional C's in the LAUs
affecting the response of microfilter in some way and messing up your
ADSL. Remember that the POTS side is the filtered side not the ADSL which
is straight through.

There are also some reports that connecting the unbalanced ring line back
into the NTE filter is not a good idea as it injects noise and thus
reduces the ADSL performance. So there maybe a case for only bring 2 & 5
from the NTE to your patch panel but deriving the ring signal there with
a single, (proper sized) C for distribution.

--
Cheers
Dave. pam is missing e-mail

I read some posts on that - but it added that using a PBX master LAu
and therefore a local capaictor for each phone was the solution -
hence the way I am going.

I suppose if I have problems all I would have to do is add a single
link at the patch panel for ringing back to 3 at the NTE5, and swap
LAU master for LAU secondary.

On 24 Feb, 13:06, John Rumm wrote:

This is because some bright spark numbered the pins in opposite
directions on plugs and sockets. So the correct assignments are pin1 on
socket goes to pin 6 on plug, 2-5 3-4 4-3 5-2 6-1

So does that mean standard phones with BT 431 plugs pre-wired will not
work ? as they will expect ringing on 3 and it will be on 4

Should all work out nicely in the end!


You right I had forgotten that BT went their own way on numberring -
and annoyingly I did know this.

I'll find out today if it works !

On 25 Feb, 11:38, Andy Wade wrote:


and recreated at the Telephony Port of the filter. This is may be
achieved using a 1.8 µF capacitor between line B (pin 5) and the bell
wire (pin 4) at the Telephony Port."

ahhh ... meets my needs then ? glad BT thought of me :-)


I'll only have 2 & 5 connected across to Patch Panel - as mentioned
that can help prevent Broadband degradation due to unbalanced ring
back - also avoid third wire acting as aerial when no phone off hook.

On 25 Feb, 12:51, "Osprey" wrote:
On 25 Feb, 11:38, Andy Wade wrote:

and recreated at the Telephony Port of the filter. This is may be achieved using a 1.8 µF capacitor between line B (pin 5) and the bell
wire (pin 4) at the Telephony Port."

ahhh ... meets my needs then ? glad BT thought of me :-)

I'll only have 2 & 5 connected across to Patch Panel - as mentioned
that can help prevent Broadband degradation due to unbalanced ring
back - also avoid third wire acting as aerial when no phone off hook.


As mentioned in one of the replies, I think the Tech sheet of the
manufacturer was mixing up BT socket & plug numbering ...
I finished my CAT 5 termination today and all works perfectly.

For ease of use I have created 2 new 'NTE5 masters' in Node zero ...
used a pre-installed piece of CAT5 to do this from the BT demarc
point.
Did this so in the event of any line issues I can simply pull off
lower half front plates of NTE5 to isolate house from lines.
To avoid any test issues I removed the Out-of-Service resistors from
these 'new' NTE5's ...
I just connected A+B legs between the BT NTE5's and my own.

I then connected A+B on my phone only line to Patch panels (2 & 5 on
NTE5 to B & A resp) made sure I had -48V on B.

The PBX master LAU then generates the local ringing via in-built
capacitor. (as it should)


On the 2nd line - I used a Clarity microfilter faceplate, I again
distributed only filtered POTS (2 & 5) to the voice patch panel, and
A&B to my DSL router.

Glad to say all working fine.

I was pretty pleased out of 32 terminated sockets only one did not
test properly with LAN tester ... that had a bad connection on one pin
on the outlet.