Kitz Forum

Broadband Related => Telephony Wiring + Equipment => Topic started by: 4candles on February 19, 2016, 02:32:27 PM

Title: Home wiring rules & regs
Post by: 4candles on February 19, 2016, 02:32:27 PM
Perusing kitz's 'Breach of Copyright' thread, I noticed the paragraph -

Quote
You are NOT allowed to replace any old style master sockets with an NTE5 socket yourself, and this should only be performed by a BT Openreach engineer. Failure to obey these rules may result in prosecution and/or a fine by BT.

As a potential serial criminal, I would be interested in whether this is really the case, or just something that BT would like us to believe.

Anyone (yes, I'm looking at you Mr Sheep  ;) ) know the facts?
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 19, 2016, 05:41:19 PM
"As a potential serial criminal ...... " pmsl.  :lol:

I'm afraid I don't have any 'Hard and fast' documentation I can post up, regarding this issue. My own personal take on it is to treat it with a pinch of salt, although kitz will have had to post up the company line at that time in history.

Most new-builds these days will see a variety of 'Builder-run' internal wiring and an array of brushed-steel type faceplates already fitted when we turn up to connect the premises to our network.
There are even master sockets incorporated into faceplates that have 'Banked' services. The same faceplate will generally incorporate a TV aerial point, 240v socket outlet and a telephone point, so it's impossible for us to install our own NTE5 demarcation point, unless we re-wire the telephony service. Obviously, this is met with looks of horror.  :)

So, as I said at the start ....... treat it with a pinch of salt. The engineers would only raise a TRC (Timescale Related Charge) if the master socket you have installed is causing a fault.  :) 
Title: Re: Home wiring rules & regs
Post by: gt94sss2 on February 22, 2016, 08:34:47 PM
Perusing kitz's 'Breach of Copyright' thread, I noticed the paragraph -

Quote
You are NOT allowed to replace any old style master sockets with an NTE5 socket yourself, and this should only be performed by a BT Openreach engineer. Failure to obey these rules may result in prosecution and/or a fine by BT.

As a potential serial criminal, I would be interested in whether this is really the case, or just something that BT would like us to believe.

Its been a long time since I have looked into this but it is against the law to mess around with the BT master sockets - from memory its considered interfering with the PSTN.

Now, in practise, I can't say how often Openreach will take action though they may charge a end-user to rectify/fix a problem BUT there have been instances in the past where someone messing around with a master socket has inadvertently managed to damage BT's network - at that point the heavens open up from a very high height..
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 22, 2016, 08:54:39 PM
One doesn't need to simply mess with the master socket to cause mayhem, and possible serious injury to unassuming OR engineers.
More than a few times over the decades, we've had instances whereby the EU has run a mains cable under a carpet and got it, and the telephone extension cable caught on the carpet gripper ....... subsequently chucking 240v along our network back to the MDF.

We used to also frequently get the 'Ghost 999' calls, although haven't seen or heard of one for quite a while now ?? This is where the extension wiring in the house has an 'Earth contact' (Insulation rubbed away, again, usually under the carpet where it's walked on), and it would 'Tap' the emergency services 911 (never 999 ??).
One of the older BT guys on here would probably be able to give a reason why it would 'Tap' this number out ..... Loop/Dis dialling or something similar ?? Not my forte I'm afraid.

So, although you are absolutely correct about the licit stance with master sockets, one can do as much damage without even touching said item.  ;) :)
Title: Re: Home wiring rules & regs
Post by: licquorice on February 22, 2016, 09:19:49 PM
That's why the emergency number was 999 and not 111 in the early days. Open wires shorting could easily tap 3 times with longer break between the shorts to emulate loop disconnect dialling. Much harder to make 9 quick shorts - break 9 quick shorts - break 9 quick shorts. With the old pre-payment phone boxes, the dial was not operative unless money had been placed in the coin box (it was returned if no reply). To make free calls you could tap the receiver rest to emulate dial pulses. Low numbers were easy to judge but 8's and 9's were harder.  ;)
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 22, 2016, 09:23:17 PM
Thank you, Licq.  :)

I remember as a kid tapping the switch hooks on my parents phone to try and set up a call ...... but this was more for mischief as we never had anyone to call back then.  :)
Title: Re: Home wiring rules & regs
Post by: licquorice on February 22, 2016, 09:30:47 PM
I got quite adept at it as a schoolboy. Living out in the sticks, I often needed the parents to pick me up from the bus stop a couple of miles away if I missed the one bus into the village. It was fairly easy to tap 364 from the phonebox without putting any money in. :-[
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 22, 2016, 09:34:38 PM
Ha ha ....... I don't think you'll be on 'Crimewatch' this month, but I'll keep a look-out, just in case.  :)
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 22, 2016, 09:51:48 PM
I was unaware that the American 911 was mapped to the UK 999.  ???

I know, due to "meddling by Europe"*, that 112 is mapped to 999.



* Don't get b*cat started . . .  >:(
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 22, 2016, 09:53:42 PM
The Cat strikes again ...... you've jogged my memory and it was indeed classed as a '112 fault' that we would pick up.  :blush:
Title: Re: Home wiring rules & regs
Post by: licquorice on February 22, 2016, 10:00:06 PM
Ah, 112 makes much more sense, far easier to tap out with intermittent shorts.
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 22, 2016, 10:00:57 PM
Yup ...... it all comes together now,  :)
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 22, 2016, 10:01:44 PM
The Cat strikes again ...... you've jogged my memory and it was indeed classed as a '112 fault' that we would pick up.  :blush:

 :thumbs:
Title: Re: Home wiring rules & regs
Post by: renluop on February 22, 2016, 10:54:32 PM
Wasn't there also something called "back dialling" or making a connection somehow with a not completely inserted coin?

Confession I lived in Essex once and my girl friend (now SWMBO) worked in Warwickshire. Her exchange was not yet on STD, so the calls I made via the operator were quite expensive. I found I could dial into a near major exchange that was enabled and use the local code from there to the girl friend's. ;D It made long distance courtship a lot cheaper.

Someone told me later it was theft from GPO of a small quantity of electricity. ::)
Title: Re: Home wiring rules & regs
Post by: licquorice on February 23, 2016, 08:47:38 AM
Also in the days of 'Local' calls it was possible to sometimes make what would be classified as a trunk call via a series of linked local calls by dialling the code for one exchange followed by the local code to another exchange. This was only possible if the exchange in question had a secondary route out as well as the route back to the parent exchange. In theory it shouldn't have been possible as the VMB (vertical marking bank) on the incoming group selectors from the parent should have had a strap to prevent an 8 (the usual code for a second route out, 9 being the parent) being dialled but a lot of exchanges didn't have the strap. The only downside was the circuits were un-amplified so could be quite faint when concatenating them.
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 23, 2016, 12:03:53 PM
I know, due to "meddling by Europe"*, that 112 is mapped to 999.

Not long ago, I was making a call.  It answered very quickly, the voice said 'Emergency, which service do you want'.  I stuttered and apologised (*), explaining that I had clearly mis-dialled, and the call ended quickly and amicably.

Being a fancy DECT phone it kept a log of dialled numbers so I could see that I had indeed mis-dialled.  What I couldn't figure out was why I had been connected to '999' when it didn't even contain these digits, let alone commence with them.   Later the penny dropped, I'd probably been 'stung' by one of these pesky mappings. >:(

Also managed once to literally dial 999 by mistake.  My employer's PBX employed the usual, dial '9' for an outgoing line.  For some reason I didn't think the '9' had worked.  So I pressed '9' again, and again, and again...   :-[

* My understanding is, if you ever do call Emergency by mistake, always explain - don't just hang up, else they might be left wondering if somebody is in trouble.
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 23, 2016, 12:18:03 PM
Incidentally, while the reasons for choosing '999' have been explained, it does have a downside that explains why it wasn't universally adopted... in the days of rotary dialling, it took a significantly longer time to dial 999 than 112, or even 911.    In a true emergency, these extra seconds might count.   :-\
Title: Re: Home wiring rules & regs
Post by: renluop on February 23, 2016, 12:55:05 PM
.... The only downside was the circuits were un-amplified so could be quite faint when concatenating them.

OT, but in the bank that employed me the larger branches could have concatenated machines. IIRC the machine at the end of the line was always the slowest.
Title: Re: Home wiring rules & regs
Post by: licquorice on February 23, 2016, 02:25:19 PM
Incidentally, while the reasons for choosing '999' have been explained, it does have a downside that explains why it wasn't universally adopted... in the days of rotary dialling, it took a significantly longer time to dial 999 than 112, or even 911.    In a true emergency, these extra seconds might count.   :-\

Yes, 2.7 seconds for 999 or 0.3 seconds for 111.  Dial speed is 10pps
Title: Re: Home wiring rules & regs
Post by: atkinsong on February 23, 2016, 06:17:40 PM
Wasn't there also something called "back dialling" or making a connection somehow with a not completely inserted coin?


Yes indeed. From memory it relied on the fact that to enable 999 calls for free, whenever the dial was taken all the way round (i.e. the 9 digit), the coin mechanism was bypassed. So to dial say the digit 5, you would put your finger in 9, take it all the way round, then leave your finger in the dial and take it back as far as the 4 digit. This had the effect of pulsing the line 5 times thus dialling a 5, then all the way round again and back to the next digit, letting the dial go back to 9 minus the digit you want. Bit tricky to do but it worked!
Title: Re: Home wiring rules & regs
Post by: licquorice on February 23, 2016, 06:29:19 PM
Yes, I had forgotten about that trick. Thanks for reminding me.
Title: Re: Home wiring rules & regs
Post by: HPsauce on February 23, 2016, 06:31:52 PM
Or just tap the rest......  ;)
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 23, 2016, 06:56:21 PM
I'm calling the Police ..... this forum is riddled with ne'er-do-wells !!  ;)
Title: Re: Home wiring rules & regs
Post by: HPsauce on February 23, 2016, 10:08:33 PM
@BS, were you around in the sixties? As a destitute student back then I never ever paid for phone calls from a call box, the whole system was riddled with engineers "little handy tricks" and in "certain circles" they were very well known.
PS That included international calls.  :-X
Title: Re: Home wiring rules & regs
Post by: Dray on February 23, 2016, 10:18:05 PM
http://www.badscience.net/2007/08/rip-joe-engressia-the-original-phone-phreak/
Title: Re: Home wiring rules & regs
Post by: sheddyian on February 23, 2016, 10:26:05 PM
Regarding emergency service numbers, I beleive that in New Zealand the emergency number is 111, and has been for a long time.

This didn't cause problems with accidental pulse dialling, because their rotary dial phones are reversed.

So (I think...) dialling a 1 actually causes 9 pulses.

Which makes me wonder if the whole point of that setup was to stop exactly the criminal behaviour of ne'er do-wells back in the day, as it'd make tapping the receiver rest a lot harder - 9 taps for 1, 8 taps for 2, 7 taps for 3 etc.

Ian
Title: Re: Home wiring rules & regs
Post by: sheddyian on February 24, 2016, 12:27:42 AM
I had nagging doubts I was imagining the NZ rotary dial phone thing, but a quick Google confirms it.

Attached :

In red, a shiny BT issue rotary pulse dialling phone

In (ivory?), a New Zealand rotary pulse dialling phone.

So, dialling 999 on a UK phone creates 9 pulses three times.
Dialling 111 on an NZ phone creates 9 pulses three times!

Ian
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 24, 2016, 07:02:43 AM
@BS, were you around in the sixties? As a destitute student back then I never ever paid for phone calls from a call box, the whole system was riddled with engineers "little handy tricks" and in "certain circles" they were very well known.
PS That included international calls.  :-X

I've been around since the mid-sixties ...... so although not part of the criminality at that time, I tried to make up for it in the 70's.  ;) ;D
Title: Re: Home wiring rules & regs
Post by: atkinsong on February 24, 2016, 07:42:52 AM
Or just tap the rest......  ;)

That was for the Button A, Button B boxes. Back dialling worked with the newer STD boxes!
Title: Re: Home wiring rules & regs
Post by: licquorice on February 24, 2016, 08:26:47 AM
Or just tap the rest......  ;)

That was for the Button A, Button B boxes. Back dialling worked with the newer STD boxes!

There would be no point in doing either on the newer boxes, they were pay on answer so the dial was operative as normal anyway.
Title: Re: Home wiring rules & regs
Post by: licquorice on February 24, 2016, 08:30:42 AM
I had nagging doubts I was imagining the NZ rotary dial phone thing, but a quick Google confirms it.

Attached :

In red, a shiny BT issue rotary pulse dialling phone

In (ivory?), a New Zealand rotary pulse dialling phone.

So, dialling 999 on a UK phone creates 9 pulses three times.
Dialling 111 on an NZ phone creates 9 pulses three times!

Ian

I must admit I had to check if it was April 1st and then found the same picture as you did. Very confusing in the exchange with the selector banks effectively numbered upside down.
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 24, 2016, 09:37:49 AM
I must admit I had to check if it was April 1st and then found the same picture as you did. Very confusing in the exchange with the selector banks effectively numbered upside down.

Heh heh, glad to see I'm not the only one who was dubious of Ian's claims, re NZ dials.  By the time Ian posted the pics I'd also followed the trail, and found the same photos on a wikipedia page.  Astonishing.
Title: Re: Home wiring rules & regs
Post by: WWWombat on February 24, 2016, 10:29:00 PM
Sweden also had an odd dial, having moved zero to the other end of the dial.

I guess that would mean dialling emergency 112 would result in 2 pulses, 2 pulses, 3 pulses.

I also recall being told that one reason we chose 999 was because level 9 on rural strowger exchanges was already the route back to the parent exchange in the town ... which is where the emergency operator was located. If you were on the main exchange, dialling 99 was enough. Myth or real?
Title: Re: Home wiring rules & regs
Post by: licquorice on February 24, 2016, 10:35:14 PM
I also recall being told that one reason we chose 999 was because level 9 on rural strowger exchanges was already the route back to the parent exchange in the town ... which is where the emergency operator was located. If you were on the main exchange, dialling 99 was enough. Myth or real?

Real
Title: Re: Home wiring rules & regs
Post by: 4candles on February 25, 2016, 12:15:21 AM
I've been somewhat distracted with other things for a few days, so, re the OP, a belated thanks to BS for the elucidation. Further searching suggests it's not so much a law or statute, but rather a question of breaching the Class Licence for the Running of Branch Telecommunication Systems (https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwiZ8MXBzo7LAhVEvA8KHUjQD7gQFggqMAE&url=http%3A%2F%2Fwww.samhallas.co.uk%2Frepository%2Fdocuments%2Foftel_code_1.pdf&usg=AFQjCNFvjib_sLobHlQxwHlVzSWs_Vm7-A).

I see that that the thread has evolved into an interesting discussion on the various methods of hacking the phone system, and I plead guilty to all the above.

Would you also take into consideration, m'lud, the following:

Coinbox off a UAX - dialling 0 for the operator would light a red lamp on the parent exchange switchboard. But, dial 9 for the parent, then the code back out to the UAX, then 0, and bingo, it's a white light - indicating an ordinary line. Place any call you like, and it was booked to the coinbox number.

And the easiest of all - placing a reverse charge call to a coinbox. This was subsequently scuppered when the pay on answer boxes produced a 'cuckoo' two tone sound to alert the operator.

There's no fun at all in System X.   :no:
Title: Re: Home wiring rules & regs
Post by: Black Sheep on February 25, 2016, 07:11:40 AM
There's no fun at all in System X

pmsl.  ;D
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 25, 2016, 09:40:25 AM
I awoke in the night, thinking of this thread, and thinking of the fact I have a perfectly functional Type 706 telephone in a cupboard, converted for modern wiring.  I'd used it for a while but banished it to a cupboard when DSL was launched, thinking it might spoil my line.  Actually though, knowing a little more than I did then, as long as it is filtered I can think of no particular reason it should be detrimental?

I have just attached it.   The Loop Disconnect Dialling still works.  And indeed - simply spinning the dial, hearing the dial pulses, awakens memories long forgotten.    Seemed to hurt my finger tip though, maybe we all developed/evolved tougher finger tips in these days?

As for an incoming call, wow - the ringer.  We still hear them occasionally on old TV series that are endlessly recycled on DTV channels but somehow, having one in the same room is still a surprise.  And a welcome one.

:)
Title: Re: Home wiring rules & regs
Post by: vic0239 on February 25, 2016, 10:07:40 AM

As for an incoming call, wow - the ringer.  We still hear them occasionally on old TV series that are endlessly recycled on DTV channels but somehow, having one in the same room is still a surprise.  And a welcome one.

:)

Indeed nostalgia is a wondrous thing.  :)

I have a roomful of vintage type phones mostly GPO and mostly for display, but 12 of them are “live” connected to my little automatic switchboard. I’m not permitted to have them all ring on an incoming call  :no: , but one or two throughout the house do.  :cool:
Title: Re: Home wiring rules & regs
Post by: 4candles on February 25, 2016, 10:46:28 AM
Actually though, knowing a little more than I did then, as long as it is filtered I can think of no particular reason it should be detrimental?

Quite so, 7LM, no reason at all.

On the filtered side of my VDSL plate, I have a modern 746 look-alike for standby in case of a power cut, but the nasty little warbler inside is disconnected. Instead, ringing is provided by a Bell Set 26, suitably modified with a 3K resistor between the coils. It sits between two closely spaced shelves, out of sight, and the cover is not fitted, so it's really loud! A wonderful sound, and absolutely no effect on ADSL.   :)
Title: Re: Home wiring rules & regs
Post by: WWWombat on February 25, 2016, 11:05:33 AM
There's no fun at all in System X.   :no:

There is when you're writing the code in it!

Well, maybe not System X exactly, but you know what I mean
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 25, 2016, 04:23:16 PM
Reading 4C's most recent post jogs my memory that I really should convert the bell-circuitry in my 1956 dated, bright red, Type 332 telephone (http://forum.kitz.co.uk/index.php/topic,13187.msg248598.html#msg248598). Once that has been done, I can then disconnect the infernal electronic noise generator of the £4-99 Tesco Value wall-mounted phone, installed in the hall.
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 25, 2016, 07:35:14 PM
Reading 4C's most recent post jogs my memory that I really should convert the bell-circuitry in my 1956 dated, bright red

Does it really need much conversion?

I have seen it stated that a series resistor is needed with old phones, to reduce the REN to less than 4, so that other phones in the home will still work.   But realistically speaking, I'd have thought that as long as other phones are electronic, and powered, their REN would be negligible, and so would still work with a single REN 'hog'.

The equation is complicated even further by the fact that, in a DSL equipped home,  each individual phone usually gets its own ring signal, from its own micro filter.   The energy to make any unpowered phones ring is still shared among all, of course.  So can't make up my mind if that helps if not.   ???
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 25, 2016, 10:19:38 PM
With a centralised filter (specifically a NTE2005, if I remember correctly), there are no micro-filters in use within The Cattery. All my telephones will make a noise when there is an incoming call . . . they each have the relevant capacitor in series with their infernal tone callers.

It will be easy enough to insert a 3.3 k Ohm resistor in series with the 332's bell, I just need to fit the resistor either between T1 - T2 or T11 - T12. (I forget which strap I removed to take the bell out of circuit.)  :)
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 25, 2016, 10:35:59 PM
Yes I am sure it will work,  but a series resistor will reduce the force with which the gong is struck by the clapper.  It would seem a shame if that unnecessarily reduces the volume, hence why I question the need for a series resistor at all.

My own phone, mentioned above, was converted before I bought it.   If I can find the time I will have a peek inside, and see if a resistor has been fitted.
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 25, 2016, 10:50:12 PM
Yes I am sure it will work,  but a series resistor will reduce the force with which the gong is struck by the clapper.  It would seem a shame if that unnecessarily reduces the volume, hence why I question the need for a series resistor at all.

The simplest thing would be for me to test it with and without the resistor.

I just need to wait for that round tuit to roll in my direction.  ;)
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 25, 2016, 11:05:24 PM
The simplest thing would be for me to test it with and without the resistor.

Arguably, if mine already has a resistor, I could try removing it.  That might be, and I apologise for what I am about to say, the path of least resistance.   :D

But as for Tuits, mine invariably seem to quickly go pear-shaped these days, so maybe better you do it after all.    :-[

Apols BTW for an empty post a moment ago, not sure how it happened, hope nobody noticed. 
Title: Re: Home wiring rules & regs
Post by: vic0239 on February 26, 2016, 09:46:22 AM
Information and instructions on converting old telephones to the current system can be found here: http://www.britishtelephones.com/pstconv1.htm (http://www.britishtelephones.com/pstconv1.htm), excellent site.
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 26, 2016, 03:33:27 PM
I have had a peek inside my 706.  It has *(see ps) no resistor fitted, and appears to ring and function perfectly.  The common base-station which serves my DECT handsets and answerphone, also appears to ring and function perfectly.    :)

With reference to the internal picture of a 706 here...

 http://www.britishtelephones.com/tranchan.htm#converted

...the location the 3k3 resistor is fitted (Terminals 4-5) is occupied by an original looking shunt, like the one shunting 5-6.   Marginally off-topic, but then this is a wandering thread... I assume such a resistor would also have been fitted to the phones, to reduce the REN, when an extension was legitimately added to a circuit, hence the removable shunt?  Am I Right? Wrong?


PS Since composing above I have found information stating that some bells were 1k resistance, others were 4k.  Mine is 4k, hence no resistor is needed, which proves nothing in regard to 1k bells.  I actually suspect my phone has not in fact been converted at all, but was probably supplied with modern plug attached in the first place, there was after all an overlap in the technologies.   :-[
Title: Re: Home wiring rules & regs
Post by: vic0239 on February 27, 2016, 11:12:40 AM

...the location the 3k3 resistor is fitted (Terminals 4-5) is occupied by an original looking shunt, like the one shunting 5-6.   Marginally off-topic, but then this is a wandering thread... I assume such a resistor would also have been fitted to the phones, to reduce the REN, when an extension was legitimately added to a circuit, hence the removable shunt?  Am I Right? Wrong?


Just opened up my 706 from 1962 and I have fitted a resistor across T4-T5, the bell motors being 1000 ohm. You are correct in your assumption of their purpose, but it depends on how the ringing current is supplied whether they are necessary. If each extension socket utilises a filter then each will be capable of providing sufficient current due to the filter having its own capacitor, but if the filtering is centralised there could be an issue with multiple phones of this type connected. Using multiple filters can introduce other annoyances such as bell “tinkle” when dialling from the 706 if you have additional phones like this.

I think the "shunt" between T5-T6 this is just a strap to facilitate connecting varying configurations of the circuit board depending on how the phone was being used.
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 27, 2016, 08:17:16 PM
It would be interesting to know whether there was any significant loudness reduction from the 1k ohm bells, after the 3k3,series resistor was added.   Logically, I'd say there must be a reduction, since the power absorbed by the bell will be less than what was originally intended.   :(


Similarly of course, were phones that left the factory with 4K bell coils quieter than those with 1K coils?

Edit:  Remove gibberish calculations, shouldn't try to calculate anything after beer.   :D
Title: Re: Home wiring rules & regs
Post by: vic0239 on February 28, 2016, 04:12:29 PM
It would be interesting to know whether there was any significant loudness reduction from the 1k ohm bells, after the 3k3,series resistor was added.   

By no means a scientific measurement, but using my own auditory sensors I could not discern any difference in volume when the resistor was removed from the circuit. Certainly nothing to diminish the effectiveness of the bells.
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 28, 2016, 05:50:33 PM
With reference to the internal picture of a 706 here...

 http://www.britishtelephones.com/tranchan.htm#converted


I'm surprised I didn't notice it when you first posted the link -- but the picture shows a converted 746, not a 706! Anyhow they are both members of the 700 series. (To state the obvious.)
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 28, 2016, 06:22:18 PM
I'm surprised I didn't notice it when you first posted the link -- but the picture shows a converted 746, not a 706! Anyhow they are both members of the 700 series. (To state the obvious.)

I'm a little confused (some would say 'Yes, we know'   :D )

But the web page to which I linked has both 706 and 746 'converted' pictures.  For some reason, not understood to me as I am not expert in html, the link opens on my browser at picture of a 746, near end of the page.  But scrolling, up a 706 can be seen above it on the same web page, and that is the picture I was referring to.   

Or am I even more confused that I thought?    ???
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 28, 2016, 06:33:32 PM
The train of events that you have described are exactly that which I experience. (Taking the link opens up the page at the image of the 746.  ??? )

Anyhow, b*cat is also easily confused!

 :friends:
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 28, 2016, 06:46:39 PM
Oddly enough, I also have a 746 that I bought in a local antique shop a few years ago.   I had never got around to converting it as I had never got around to figuring out what was needed.   But thanks to this thread, I feel more confident and may well get on with it.

One small problem is that there is no longer full bell-wire continuity between all of my sockets, having been disconnected in an effort to 'optimise' for DSL.   So the phones would (a) need to each have a micro filter for ring signal and (b) would each tinkle, as the other one dialled.

But heck, the bell tinkle will be another nostalgic moment, a familiar sound to many who installed their own extensions that were not entirely 'legit', back in the day. :blush:
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 28, 2016, 07:10:51 PM
One small problem is that there is no longer full bell-wire continuity between all of my sockets, having been disconnected in an effort to 'optimise' for DSL.   So the phones would (a) need to each have a micro filter for ring signal

A micro filter should not be necessary. Just fit a strap between terminals T17 & T18.

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(b) would each tinkle, as the other one dialled.

But heck, the bell tinkle will be another nostalgic moment, a familiar sound to many who installed their own extensions that were not entirely 'legit', back in the day. :blush:

Instead of the strap, mentioned above, use a Thermistor 1A-1.

I'll refer you to diagram N846 (http://www.samhallas.co.uk/repository/n_diagrams/0000/N846.pdf).  :)
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 28, 2016, 07:32:03 PM
Thanks B*cat.   It should have been obvious that a filter was not a necessity as these phones functioned back in the 1970s, before filters (or even 'master sockets') had appeared.   :)

I am certain I can find a 3k3 resistor.  And I can probably find a BT lead with plug, that I can cannibalise to make a lead.  I know that I won't find a suitable thermistor in my toy box so that will have to be ordered, although I am sure I can find enough other bits and bobs on my 'want list' to merit an order from Maplin or RS.   :)
Title: Re: Home wiring rules & regs
Post by: burakkucat on February 28, 2016, 09:30:03 PM
If you would like the proper lead, in the right colour, with a 431A plug at one end and the moulded on square grommet at the other end, along with spade connectors for the wires, then have a quick search on eBay. Here's two I found earlier --

Just the line cord (http://www.ebay.co.uk/itm/NEW-LINE-CORDS-for-700-Series-GPO-PHONES-ALL-COLOURS-AVAILABLE-upto-3m/281929320932). Both the handset cord and the line cord (http://www.ebay.co.uk/itm/706-746-711-741-GPO-TELEPHONES-NEW-CURLY-LINE-CORDS-in-pairs-ALL-Colours-/281929320938).
 
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on February 28, 2016, 09:43:10 PM

Yes thanks, I had found the eBay traders.

Whilst I am tempted to do it with proper parts, my 746 phone still has at least the original grommet, unoccupied, that I think I can bodge/modify for whatever old lead I can find.   It won't be as neat as a new lead with correct colours, spade terminals and moulded grommet, but will be better than nothing - at least until I satisfy myself the phone, bell and handset all work.
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on March 01, 2016, 10:56:37 PM
Slightly embarrassing that it has taken me this long to notice, having declared my 706 as 'working' several days ago, but today I actually used it to conduct a conversation using it... And I found that the sound of my own voice was really quite distracting, 'sidetone', I think it is called.   

From brief research, the 706 was meant to have good anti-sidetone circuitry, for its day.  So the question is, how effective should that be? 

I am not seeking component-level guidance for faults that might cause excessive sidetone, merely general guidance as to what level of sidetone was 'normal', and what level might suggest a fault that merits investigation.   :)
Title: Re: Home wiring rules & regs
Post by: burakkucat on March 01, 2016, 11:10:02 PM
I'll point you to the plug-in regulator that is present in the Type 706 telephones. The regulator can either be in circuit or removed from circuit just by pulling its small PCB out, up-ending it and plugging it back in the "other way round".

See Note C in diagram N806 (http://www.samhallas.co.uk/repository/n_index/index.php?dir=0000/&file=N806.pdf).

I wonder if the regulator has been taken out of circuit?  :-\
Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on March 02, 2016, 12:13:57 AM
Thank you, I will take a closer look at the regulator.

With reference to the following page (should show a 706 'tear down'), the regulator PCB appears to be present, and the right way around.  That doesn't exclude the possibility that, for some reason, it's not working right.  Further analysis will have to wait for daylight, availability of time, and full sobriety. 

www.britishtelephones.com/t706dismantle.htm

I note the author of that article is credited as  Sam Hallis, consistent with the link you posted.  ;)

Title: Re: Home wiring rules & regs
Post by: sevenlayermuddle on March 02, 2016, 10:40:02 AM
I think I am going to conclude my sidetone is within normal limits.  The main components affecting it seem to be R1, R2, C1B, the regulator and the transformer.  Main suspects would be the resistors and capacitors, but the Rs are close to value, as the is cap, and the cap' has no obvious leakage path.

I have however fixed a minor defect... In reply 36 to this thread, I mentioned the nostalgia of 'hearing the dial pulses'.  Looking at the circuit diagram, they're not meant to audible - the receiver being shorted out by a pair of dial contacts when it's off rest. :-[

A brief and gentle wipe at the affected dial contacts with abrasive paper and a coating of switch cleaner has rendered the pulses near-silent, as they should be.  Don't ask me why they are not totally silent, I guess the dial contacts are not quite achieving 0 ohms.  But I do seem to remember it was not unusual to hear very faint pulsing in the receiver when dialling, so I think I'm going to leave well alone.   :)
Title: Re: Home wiring rules & regs
Post by: burakkucat on March 02, 2016, 04:42:37 PM
Thank you for the update on your examination and refurbishment.

I can well remember a two tone green Type 706 telephone (PCB version) from the early 1960s and needing to disassemble/reassemble it. But I can't remember the reason why . . .  ::)