Hello.
as header really.
Phone is an old bakelite gadget with 3 wires that would have been hardwired
into a junction box.
Can this be connected to a more modern plug in BT socket and if so ~ how?

Many thanks
Nick.

In article ,
Nick wrote:
Hello. as header really. Phone is an old bakelite gadget with 3 wires
that would have been hardwired into a junction box. Can this be
connected to a more modern plug in BT socket and if so ~ how?

http://web.ukonline.co.uk/freshwater/pstconv1.htm

--
*Learn from your parents' mistakes - use birth control.

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

Nick wrote:
Hello.
as header really.
Phone is an old bakelite gadget with 3 wires that would have been hardwired
into a junction box.
Can this be connected to a more modern plug in BT socket and if so ~ how?

Many thanks
Nick.


Of course it can.


The whole exchange kit is backwards compatible to the year dot, except
pre loop disconnect dial stuff won't off-hook get you an operator to ask
to connect you...But you can dial by tapping the off-hook switch..;-)

I cannot remember which wires go where though: there will be two signal
and one bell wire..so if you can identify which plug wires to connect to
in the first place..two will have about 50V DC across them, so that's
one way to find them....the bell wire will give you a nasty tingle when
someone rings you, so conncect theh hamster across various pairs and
dial in from yer mobile. When he leaps, that's teh bell wire..
there are only a finite number of combinations to try, and you won't
screw the exchange up. Not sure about the hamster tho..

Try em till it works..

In article ,
The Natural Philosopher wrote:
I cannot remember which wires go where though: there will be two signal
and one bell wire..so if you can identify which plug wires to connect to
in the first place..two will have about 50V DC across them, so that's
one way to find them....the bell wire will give you a nasty tingle when
someone rings you, so conncect theh hamster across various pairs and
dial in from yer mobile. When he leaps, that's teh bell wire..
there are only a finite number of combinations to try, and you won't
screw the exchange up. Not sure about the hamster tho..

Problem with older phones is the bells are low impedance with effectively
a REN of several and will likely stop any others in the house ringing. But
there are ways round this.

--
*Filthy stinking rich -- well, two out of three ain't bad

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

Dave Plowman (News) wrote:
In article ,
The Natural Philosopher wrote:
I cannot remember which wires go where though: there will be two signal
and one bell wire..so if you can identify which plug wires to connect to
in the first place..two will have about 50V DC across them, so that's
one way to find them....the bell wire will give you a nasty tingle when
someone rings you, so conncect theh hamster across various pairs and
dial in from yer mobile. When he leaps, that's teh bell wire..
there are only a finite number of combinations to try, and you won't
screw the exchange up. Not sure about the hamster tho..

Problem with older phones is the bells are low impedance with effectively
a REN of several and will likely stop any others in the house ringing. But
there are ways round this.

BUT EVERYONE ON UK.TELECOM.BRODBAND SWERARS BLIND MODERN PHONES DON'T
USE THE BELL WIRE ANYWAY...

On Fri, 15 Feb 2008 00:41:08 +0000, The Natural Philosopher
wrote:

Dave Plowman (News) wrote:
In article ,
The Natural Philosopher wrote:
I cannot remember which wires go where though: there will be two signal
and one bell wire..so if you can identify which plug wires to connect to
in the first place..two will have about 50V DC across them, so that's
one way to find them....the bell wire will give you a nasty tingle when
someone rings you, so conncect theh hamster across various pairs and
dial in from yer mobile. When he leaps, that's teh bell wire..
there are only a finite number of combinations to try, and you won't
screw the exchange up. Not sure about the hamster tho..

Problem with older phones is the bells are low impedance with effectively
a REN of several and will likely stop any others in the house ringing. But
there are ways round this.

BUT EVERYONE ON UK.TELECOM.BRODBAND SWERARS BLIND MODERN PHONES DON'T
USE THE BELL WIRE ANYWAY...

Some modern phones use the bell wire, some modern phones don't.
Besides, that is not relevant to the REN. Most modern electronic
phones are high impedance and don't load the phone line with low
impedance bells and electromagnetic earpieces. The ring detection is
done electronically, maybe across the pair, maybe from the ring line,
either way, it has very little effect on the rest of the circuit.


--
Regards, Paul Herber, Sandrila Ltd.
Electronics for Visio http://www.electronics.sandrila.co.uk/

In article , Nick philremovethisbit
writes

Phone is an old bakelite gadget with 3 wires that would have been hardwired
into a junction box.
Can this be connected to a more modern plug in BT socket and if so ~ how?

Yes. I'm assuming it's not so old that it doesn't have the BT standard
terminal layout - two rows of screw terminals, 1 to 9 on the top row and
10 to 19 on the bottom row.

Get yourself a BT plug-to-spade-connector lead (aka "a line cord").
Ebay item 170186909828 for example.

Open the phone and remove existing cord.

Remove strap between terminals 4 and 5 and insert a 2.2kohm 1/4W
resistor. This is to reduce the current drawn by the bell - the bells
in old phones are low impedance. You may see "500" on the bell coils -
this is their impedance (500+500). Ensure there is a strap between
terminals 5 and 6 and connect the BLUE wire from the cord to terminal 6.

Ensure there is a strap between terminals 8 and 9 and connect the RED
wire from the cord to terminal 8.

Ensure terminals 16, 17, 18 and 19 are all linked with straps and
connect the WHITE wire from the cord to terminal 18.

Connect the GREEN wire of the cord (it's unused) to terminal 14.

Test.

Be warned that old phones like this may degrade data calls using a modem
or affect a broadband connection.

Be aware that the DC voltage on a phone line is 48V, and that the
ringing current is ~90V AC. Don't work on a phone that's plugged in, as
the ringing voltage can be hair-raising.

--
(\__/) Bunny says NO to Windows Vista!
(='.'=) http://www.cs.auckland.ac.nz/~pgut00...ista_cost.html
(")_(")

In article ,
The Natural Philosopher wrote:
Problem with older phones is the bells are low impedance with
effectively a REN of several and will likely stop any others in the
house ringing. But there are ways round this.

BUT EVERYONE ON UK.TELECOM.BRODBAND SWERARS BLIND MODERN PHONES DON'T
USE THE BELL WIRE ANYWAY...

Some do, some don't.

--
*People want trepanners like they want a hole in the head*

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

On Thu, 14 Feb 2008 23:45:24 +0000, The Natural Philosopher wrote:

the bell wire will give you a nasty tingle when someone rings you,

True(ish).

so conncect theh hamster across various pairs and dial in from yer
mobile. When he leaps, that's teh bell wire..

Or the incoming pair...

--
Cheers
Dave.

In article et,
"Dave Liquorice" writes:
On Thu, 14 Feb 2008 23:45:24 +0000, The Natural Philosopher wrote:

the bell wire will give you a nasty tingle when someone rings you,

True(ish).

Especially if you are stripping it with your teeth at the time.
Telex lines were even worse (up to 160V peak AC when ringing).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Fri, 15 Feb 2008 08:45:09 +0000, Mike Tomlinson
wrote:

In article , Nick philremovethisbit
writes

Phone is an old bakelite gadget with 3 wires that would have been hardwired
into a junction box.
Can this be connected to a more modern plug in BT socket and if so ~ how?

Yes. I'm assuming it's not so old that it doesn't have the BT standard
terminal layout - two rows of screw terminals, 1 to 9 on the top row and
10 to 19 on the bottom row.

Not if it's a bakelite one - these have a different terminal layout.
The connections varied depending on the type of phone, ie normal,
shared service or whatever.

Is there a type number printed on the base of the phone, such as 332,
312, or similar?

--
Frank Erskine

In an earlier contribution to this discussion,
The Natural Philosopher wrote:


Problem with older phones is the bells are low impedance with
effectively a REN of several and will likely stop any others in the
house ringing. But there are ways round this.

BUT EVERYONE ON UK.TELECOM.BRODBAND SWERARS BLIND MODERN PHONES DON'T
USE THE BELL WIRE ANYWAY...

So? I thought this thread was about *old* telephones - which *do* use the
bell wire when connected to a modular socket - and even when hardwired if
they were not the first in line.

ISTR that old bells had an impediance of 1k ohms - thus having a REN of 4 -
whereas later ones with a REN of 1 had an impedance of 4k ohms. So,
basically, you need to wire a 3k ohm (some say 2.2k - not quite sure why)
resistor in series with the bell, and you're sorted.
--
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!

On 15 Feb 2008 11:57:51 GMT, Andrew Gabriel wrote:

Especially if you are stripping it with your teeth at the time.

It took me a while to work out why I was getting belts from a BT block I
was attaching lines to for an OB. It was issing with rain, I was soaked
and standing in a puddle. All the lines where controls, 4 wires or musics
ie no volts. I then remembered that we also hada DEL...

I got fed up Telex lines were even worse (up to 160V peak AC when
ringing).

Didn't think telex lines rang as such but the data is +/- 80v from a hi-z
source. I don't think I've been daft enough to come into contact with the
fed to the magnet on my Creed 444 (or any of te other mechanical telex
machines I've had in the past).

--
Cheers
Dave.

After serious thinking Nick wrote :
Hello.
as header really.
Phone is an old bakelite gadget with 3 wires that would have been hardwired
into a junction box.
Can this be connected to a more modern plug in BT socket and if so ~ how?

I can't remember the old connection colours, but just cut a lead with
plug off a modern but redundant phone. There is a web site dedicated to
the UK phone system which carries lots of information about connecting
old phones to the modern system. Impulse (loop disconnect?) dialing is
still supported by the UK exchanges, so there is no reason for it not
to work.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

In message , Roger Mills
writes
In an earlier contribution to this discussion,
The Natural Philosopher wrote:


Problem with older phones is the bells are low impedance with
effectively a REN of several and will likely stop any others in the
house ringing. But there are ways round this.

BUT EVERYONE ON UK.TELECOM.BRODBAND SWERARS BLIND MODERN PHONES DON'T
USE THE BELL WIRE ANYWAY...

So? I thought this thread was about *old* telephones - which *do* use the
bell wire when connected to a modular socket - and even when hardwired if
they were not the first in line.

ISTR that old bells had an impediance of 1k ohms - thus having a REN of 4 -
whereas later ones with a REN of 1 had an impedance of 4k ohms. So,
basically, you need to wire a 3k ohm (some say 2.2k - not quite sure why)

2.2k being a preferred value of a power series perhaps



--
geoff

On Fri, 15 Feb 2008 20:32:51 GMT, wrote:

On 15 Feb,
"Roger Mills" wrote:

ISTR that old bells had an impediance of 1k ohms - thus having a REN of 4 -
whereas later ones with a REN of 1 had an impedance of 4k ohms. So,
basically, you need to wire a 3k ohm (some say 2.2k - not quite sure why)
resistor in series with the bell, and you're sorted.

Some had two coils, which could be wired in series for 4K and parallel for
1K.

The old extension system wired the bells in series and required the coils in
parallel. the newer plug (modern type sockets) have the bells in parallel,
and require the coils in series.

The public network never had the 500 ohm bell coils in parallel in the
phone - they were always wired in series. Very occasionally private
circuits had the coils in parallel.
As you say though, in the old system the bells were connected in
series, up to (officially!) a maximum of four. Or was it six; and four
for a party line?
The early 'plan 4' system of plug and socket telephones was a bit of
fun. There had to be at least one fixed bell (usually a separate
bellset was permanently connected) and each socket had to have a break
jack to maintain continuity of the bell circuit when a phone was
plugged/unplugged.

The concept of REN didn't exist until the new system came about.

--
Frank Erskine

On Fri, 15 Feb 2008 20:13:31 +0000 (GMT), "Dave Liquorice"
wrote:

Didn't think telex lines rang as such but the data is +/- 80v from a hi-z
source. I don't think I've been daft enough to come into contact with the
fed to the magnet on my Creed 444 (or any of te other mechanical telex
machines I've had in the past).

It hurts!

I can't feel a normal 50v telephone line voltage, unless there's some
back emf putting nasties on the line. Telephone ringing voltage is a
bit uncomfortable though.

--
Frank Erskine

In article ,
Frank Erskine writes:
The public network never had the 500 ohm bell coils in parallel in the
phone - they were always wired in series. Very occasionally private
circuits had the coils in parallel.
As you say though, in the old system the bells were connected in
series, up to (officially!) a maximum of four. Or was it six; and four
for a party line?

It was 4 for the longest line length supported.

The concept of REN didn't exist until the new system came about.

Back in the days of BT approvals in Baynard House, I took a couple
of devices along to get their approvals, which was a remarkably
unscientific process.

For the REN number rating, they supply a line simulating the longest
line length, and a (704?) standard phone on the end. The phone is
ringing. You plug in your appliance. If the phone stops ringing, you
get a REN of 4, and if it carries on ringing, you get a REN of 3.
If you have bought a second sample of your appliance, you are invited
to plug that in too. If the phone carries on ringing, you now get a
REN of 1.5. If you have bought a third sample of your appliance, you
can now try connecting that. If the phone carries on ringing, you now
get a REN of 1. You can carry on going if you have even more samples
with you. When I was at GEC, it was rare for us to have more than one
sample available to take along for testing, so most of our stuff got
a REN rating of 3, even though it was probably much lower. If you
look around at phones with REN ratings, you'll find they are normally
1, 1.5, or 3, and this explains why (e.g. there was no way to get a
REN rating of 2). The first caller display units I saw had a REN
rating of 0.25, for which they must have taken 12 of them along for
testing (although testing had been taken over by BABT by then, and
they might have changed the procedure).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 2008-02-16 15:00:41 +0000, (Andrew
Gabriel) said:

Back in the days of BT approvals in Baynard House, I took a couple
of devices along to get their approvals, which was a remarkably
unscientific process.



... (although testing had been taken over by BABT by then, and
they might have changed the procedure).

Probably not. You should have seen what they did with an X.25 gateway
that I took to them at one point.

In article 47b6feb8@qaanaaq,
Andy Hall writes:
On 2008-02-16 15:00:41 +0000, (Andrew
Gabriel) said:

Back in the days of BT approvals in Baynard House, I took a couple
of devices along to get their approvals, which was a remarkably
unscientific process.



... (although testing had been taken over by BABT by then, and
they might have changed the procedure).

Probably not. You should have seen what they did with an X.25 gateway
that I took to them at one point.

How strange -- I designed X.25 switches at GEC in the 1980's,
and had to get those tested for PSS approvals in early days,
and the line modules had to get electrical approvals. One I
remember was our G.704 module which we designed to provide a
raw unstructured 2Mbit X.25 link over BT's Megastream service.
Went along to Baynard House, and the bloke took it and looked
at it, and said "that's fine". It was the first G.704 module
they'd seen, and they didn't have any tests defined for it!

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 2008-02-16 18:56:49 +0000, (Andrew
Gabriel) said:

In article 47b6feb8@qaanaaq,
Andy Hall writes:
On 2008-02-16 15:00:41 +0000, (Andrew
Gabriel) said:

Back in the days of BT approvals in Baynard House, I took a couple
of devices along to get their approvals, which was a remarkably
unscientific process.



... (although testing had been taken over by BABT by then, and
they might have changed the procedure).

Probably not. You should have seen what they did with an X.25 gateway
that I took to them at one point.

How strange -- I designed X.25 switches at GEC in the 1980's,
and had to get those tested for PSS approvals in early days,
and the line modules had to get electrical approvals. One I
remember was our G.704 module which we designed to provide a
raw unstructured 2Mbit X.25 link over BT's Megastream service.
Went along to Baynard House, and the bloke took it and looked
at it, and said "that's fine". It was the first G.704 module
they'd seen, and they didn't have any tests defined for it!

Well the problem was that this was a product that had originated in the U.S.

For some reason, best known to themselves, BT had an addressing scheme
(group number IIRC) that was 4, while in every other country it was 0.
On this particular box the addressing wasn't configurable, simply
because there was no need anywhere other than in the UK.

Anyway, the BT guy agreed to sign it off on the basis that I agreed
that we would have a software fix to allow configurability before any
were connected to their network. I suspect that he figured that if
this wasn't there, it wouldn't work with their PSS environment anyway.
All of the other HDLC and other tests had passed and they seemed more
concerned about that for some reason. There was no interest in the
hardware at all.

Imagine paying by the packet (well segment)..... but one did.

On Sat, 16 Feb 2008 00:15:16 +0000,it is alleged that Frank Erskine
spake thusly in uk.d-i-y:

On Fri, 15 Feb 2008 20:32:51 GMT, wrote:

On 15 Feb,
"Roger Mills" wrote:

ISTR that old bells had an impediance of 1k ohms - thus having a REN of 4 -
whereas later ones with a REN of 1 had an impedance of 4k ohms. So,
basically, you need to wire a 3k ohm (some say 2.2k - not quite sure why)
resistor in series with the bell, and you're sorted.

I usually use 3k3 and adjust the bell armature gap to 12/1000in to
compensate for the lower power.


Some had two coils, which could be wired in series for 4K and parallel for
1K.

The old extension system wired the bells in series and required the coils in
parallel. the newer plug (modern type sockets) have the bells in parallel,
and require the coils in series.

The public network never had the 500 ohm bell coils in parallel in the
phone - they were always wired in series. Very occasionally private
circuits had the coils in parallel.

The 2x500 ohm coils were for hysterical... err historical reasons. The
old CBS1 manual systems required the bell to be 250 ohm earth
connected, and the CBS2/CB/Auto required 1000 ohm, so the 1A bell was
designed with 2x500 ohm coils, and the 59A/B and C followed... such
was inertia within the PO (why change it, it works), that it remained
standard.

The much later (1979?) 59D bell did indeed have 2x2000 ohm coils, but
I've never seen one wired parallel for 1000 ohm, although there's no
reason it wouldn't work.

As you say though, in the old system the bells were connected in
series, up to (officially!) a maximum of four. Or was it six; and four
for a party line?

I think in some cases it was 5

The early 'plan 4' system of plug and socket telephones was a bit of
fun. There had to be at least one fixed bell (usually a separate
bellset was permanently connected) and each socket had to have a break
jack to maintain continuity of the bell circuit when a phone was
plugged/unplugged.

ITYM To _allegedly_ maintain continuity ;-)


The concept of REN didn't exist until the new system came about.

And of course American phones have a REN too... only it's not the same
as our REN, what fun!

To the OP: Make sure you connect 2x 1N4001 or similar diodes in
inverse parallel across the receiver (red/green in the handset cord on
most GPO 300/700 series phones) to prevent acoustic shock from loose
connections or dud dial offnormal contacts.. very likely in a phone of
this age, as it can really hurt, and even cause hearing damage.
Originally this would have been a metal rectifier with a lower forward
voltage, but silicon diodes at 0.5-0.6v will still take the edge off
the clicks and pops.


--
_
( ) ASCII ribbon campaign against html e-mail
X and usenet posts
/ \

In article 47b73fd7@qaanaaq,
Andy Hall writes:
On 2008-02-16 18:56:49 +0000, (Andrew
Gabriel) said:
How strange -- I designed X.25 switches at GEC in the 1980's,
and had to get those tested for PSS approvals in early days,
and the line modules had to get electrical approvals. One I
remember was our G.704 module which we designed to provide a
raw unstructured 2Mbit X.25 link over BT's Megastream service.
Went along to Baynard House, and the bloke took it and looked
at it, and said "that's fine". It was the first G.704 module
they'd seen, and they didn't have any tests defined for it!

Well the problem was that this was a product that had originated in the U.S.

For some reason, best known to themselves, BT had an addressing scheme
(group number IIRC) that was 4, while in every other country it was 0.
On this particular box the addressing wasn't configurable, simply
because there was no need anywhere other than in the UK.

Not too sure what you mean. PSS always required the DNIC to
be present (2342), whereas most other networks only required
the DNIC for calls to other networks. It was a bit like always
requiring the full international number to be dialled for a
phone call, even a local one. Actually, I thought this made a
lot of sense. Generally there's no one typing in X.121 addresses
for each connection (excluding dial-up PADs), so having short
forms of addresses was just overhead in software to recognise
(a bit of software I wrote a number of times in different
products;-). Since we sold in other countries too, we had to
cope with this though.

For the LCGN, PSS supported all 4 ranges if you subscribed to
them, although BT stopped selling new PVCs around 1985 because
their switches ran out of table space to record them. I can't
recall if other country implementations supported multiple LCGN
ranges (most didn't support PVCs, which would have removed one
of the LCGN ranges in any case).

Anyway, the BT guy agreed to sign it off on the basis that I agreed
that we would have a software fix to allow configurability before any
were connected to their network. I suspect that he figured that if
this wasn't there, it wouldn't work with their PSS environment anyway.
All of the other HDLC and other tests had passed and they seemed more
concerned about that for some reason. There was no interest in the
hardware at all.

Imagine paying by the packet (well segment)..... but one did.

Yes.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 2008-02-16 21:07:33 +0000, andrew@a17 (Andrew Gabriel) said:

In article 47b73fd7@qaanaaq,
Andy Hall writes:

Well the problem was that this was a product that had originated in the U.S.

For some reason, best known to themselves, BT had an addressing scheme
(group number IIRC) that was 4, while in every other country it was 0.
On this particular box the addressing wasn't configurable, simply
because there was no need anywhere other than in the UK.

Not too sure what you mean. PSS always required the DNIC to
be present (2342), whereas most other networks only required
the DNIC for calls to other networks. It was a bit like always
requiring the full international number to be dialled for a
phone call, even a local one. Actually, I thought this made a
lot of sense. Generally there's no one typing in X.121 addresses
for each connection (excluding dial-up PADs), so having short
forms of addresses was just overhead in software to recognise
(a bit of software I wrote a number of times in different
products;-). Since we sold in other countries too, we had to
cope with this though.

For the LCGN, PSS supported all 4 ranges if you subscribed to
them, although BT stopped selling new PVCs around 1985 because
their switches ran out of table space to record them. I can't
recall if other country implementations supported multiple LCGN
ranges (most didn't support PVCs, which would have removed one
of the LCGN ranges in any case).

You've stirred the cobwebs in the back of my mind on this one. I
did mean LCGN rather than the X.121 addressing.

IIRC, BT had 4 for SVCs and lower numbers for PVCs. This was an SVC
only product that went onto the market in about 1984 and in other
countries SVCs started at 0 so there was no need to have setting of
LCGN other than for the UK.

Phone is an old bakelite gadget with 3 wires that would have been hardwired
into a junction box.
Can this be connected to a more modern plug in BT socket and if so ~ how?

yes, same way as a new phone. Getting old cloth wire into an RJ45 is I
assume impossible, so a modern plug with a short stub of wire is
connected to the cloth cord.


Problem with older phones is the bells are low impedance with effectively
a REN of several and will likely stop any others in the house ringing. But
there are ways round this.

This is an often misunderstood issue. REN of most old mechanical bell
phones is 4. Phone exchanges are designed to guarantee all lines will
power a total REN of 4. In practice most will power rather more, as
the wire from the exchange's resistance is usually well below the
limit, hence one old phone plus a couple of modern is not normally a
problem, though it can be occasionally.


BUT EVERYONE ON UK.TELECOM.BRODBAND SWERARS BLIND MODERN PHONES DON'T
USE THE BELL WIRE ANYWAY...

Most have built in caps and don't, but some do. Connection
configurable phones can be connected up pretty much any way, and can
be reconfigured any way. These configurables were designed to be
usable as bugs too, phones were a reliable low cost way to bug people,
and an engineer call to rewire the phone connection didn't arouse
suspicion. So you might one day find a phone so wired, with mic across
the line when on hook.


To the OP: Make sure you connect 2x 1N4001 or similar diodes in
inverse parallel across the receiver (red/green in the handset cord on
most GPO 300/700 series phones) to prevent acoustic shock from loose
connections or dud dial offnormal contacts.. very likely in a phone of
this age, as it can really hurt, and even cause hearing damage.
Originally this would have been a metal rectifier with a lower forward
voltage, but silicon diodes at 0.5-0.6v will still take the edge off
the clicks and pops.

Why do you need diodes when there is already a metal diode stack in
there doing this?


Finally if you dont like dialling the long modern numbers, you can use
a handheld thingy to tone dial. Dials were fine in the days of 3
figure numbers!


NT

On Sat, 16 Feb 2008 21:33:35 +0000, Andy Hall
wrote:

On 2008-02-16 21:07:33 +0000, andrew@a17 (Andrew Gabriel) said:

In article 47b73fd7@qaanaaq,
Andy Hall writes:

Well the problem was that this was a product that had originated in the U.S.

For some reason, best known to themselves, BT had an addressing scheme
(group number IIRC) that was 4, while in every other country it was 0.
On this particular box the addressing wasn't configurable, simply
because there was no need anywhere other than in the UK.

Not too sure what you mean. PSS always required the DNIC to
be present (2342), whereas most other networks only required
the DNIC for calls to other networks. It was a bit like always
requiring the full international number to be dialled for a
phone call, even a local one. Actually, I thought this made a
lot of sense. Generally there's no one typing in X.121 addresses
for each connection (excluding dial-up PADs), so having short
forms of addresses was just overhead in software to recognise
(a bit of software I wrote a number of times in different
products;-). Since we sold in other countries too, we had to
cope with this though.

For the LCGN, PSS supported all 4 ranges if you subscribed to
them, although BT stopped selling new PVCs around 1985 because
their switches ran out of table space to record them. I can't
recall if other country implementations supported multiple LCGN
ranges (most didn't support PVCs, which would have removed one
of the LCGN ranges in any case).

You've stirred the cobwebs in the back of my mind on this one. I
did mean LCGN rather than the X.121 addressing.

IIRC, BT had 4 for SVCs and lower numbers for PVCs. This was an SVC
only product that went onto the market in about 1984 and in other
countries SVCs started at 0 so there was no need to have setting of
LCGN other than for the UK.


http://www.telephonesuk.co.uk/conversion.htm

--
Frank Erskine

On Sat, 16 Feb 2008 14:32:36 -0800 (PST), wrote:

Phone is an old bakelite gadget with 3 wires that would have been hardwired
into a junction box.
Can this be connected to a more modern plug in BT socket and if so ~ how?

yes, same way as a new phone. Getting old cloth wire into an RJ45 is I
assume impossible, so a modern plug with a short stub of wire is
connected to the cloth cord.

The nicest way is to terminate the 'cloth' cord on a bakelite Blocks
Terminal screwed to the wall just as in days of yore, then have a
short 'modern' cord from there to an adjacent NTE socket.

--
Frank Erskine