Unmodified Cream/Ivory GPO 746!!! - UK Vintage Radio Repair and Restoration Discussion Forum

twocvbloke · 16th Mar 2011, 3:58 pm

I got me a 746 again!

Now, this one I spotted with the same stall holder in Burnleh a couple of months ago, and it seems nobody wanted it, so today, I handed over £25 (seems reasonable given it's unmodified and in very good condition), and here I am with a classic phone again.

I was planning to convert it today, but unfortunately, the electronics shop that I went to for a 3.3k resistor was out of stock of that specific resistor (seems every time I go there for something specific, they never have it in stock, bad luck I guess!), so for now, I shall just give it a wipe down and look at it lovingly.

The fella told me he'd had it in his house since 1970, and was in use up until "recently" (given how I'd seen it a couple of months ago, it wasn't that recent!!), it still has the Block Terminal on the end of the cable, but is missing the nut that holds the lid on, and all the wires were disconnected, but reconnecting them all up properly and connecting it up to my linesman phone, and the phone is working great, speech is clear, the bells ring (albeit a tad roughly), so apart from the slow-mo dial (I think that's going to need stripping and lubing), it's perfect.

And now some photos (taken with my phone, haven't charged up batteries for my camera yet):

twocvbloke · 16th Mar 2011, 4:32 pm

What a stroke of luck, it still has it's dial label!!! It was just turned over...

(there is a number on there, but I thought I best blank it in case it is still actually in use)

Dave Moll · 16th Mar 2011, 5:12 pm

Quote:

Originally Posted by twocvbloke

I was planning to convert it today, but ... a 3.3k resistor was out of stock ... so for now, I shall just give it a wipe down and look at it lovingly...

Just put a link instead of the resistor for the time being. The worst that can happen as a result is that you need to disconnect your other 'phones while that one's plugged in.

russell_w_b · 16th Mar 2011, 5:13 pm

Quote:

Originally Posted by twocvbloke

'...I was planning to convert it today, but unfortunately, the electronics shop that I went to for a 3.3k resistor...'

Just get on with it and forget about the resistor. I can (almost) guarantee that it will work fine!

If my guarantee fails, then get one.

twocvbloke · 16th Mar 2011, 5:23 pm

Well, it also needs the dial sorting out, cos comparing it to my linesman phone's dial, dialling 0 showed it rotating slower by about a second, I'm just so pleased I have it, it looks very nice, shame I haven't got a little table by my sofa to put it on...

twocvbloke · 16th Mar 2011, 8:16 pm

Well, done the resistorless conversion, and on my linesman phone with the ADSL filter, it works perfectly, on the phoneline (VirginMedia, in an Ex-Cable & Wireless area which supports Pulse-dial) with one cheap binatone plugged in upstairs where I can't actually access the socket, erm, nowt, ah well, I'll just have to get the resistor, just to finish off the conversion properly.

Just that and the dial to sort, not really looking forward to that.

Dave Moll · 16th Mar 2011, 8:36 pm

When you say "nowt", do you mean that it is dead when off-hook or simply that it doesn't ring?

If the former, the problem lies elsewhere than the lack of resistor, as this is not even in-circuit when off-hook. I am, however, struggling to think what would be different between linesman and 'phone line - other than possibly line voltage.

twocvbloke · 16th Mar 2011, 8:37 pm

And a picture, I did the modern-cable-into-Block-Terminal wiring technique, rather than putting a new cable into the phone itself, mainly cos I haven't got a proper matching cable to fit it.

And I cheated with the BT, I used a white GEC one I bought off ebay last month, cos the one the phone came with is caked in paint and missing two screws from the inner two terminals, and the nut that the main screw attaches to, and also it seems the screw has fallen out and disappeared too, it's cursed I tells ya!

Still, I love this phone, bells need tinkering with (they sound uneven, and actually don't sound like the 746 I used to have), but it's ringing anyway, on the linesman at least.

twocvbloke · 16th Mar 2011, 8:40 pm

Quote:

Originally Posted by Dave Moll

When you say "nowt", do you mean that it is dead when off-hook or simply that it doesn't ring?

If the former, the problem lies elsewhere than the lack of resistor, as this is not even in-circuit when off-hook. I am, however, struggling to think what would be different between linesman and 'phone line - other than possibly line voltage.

Well, with two phones plus this one, the bells initially tinkled, then nothing, just silence, and with just the binatone upstairs (electronic phone) and the 746, nothing, just silence.

It connects the line when answered though, and hangs up too, so, I don't know, maybe the bells just want more power than the VM line is supplying.

Dave Moll · 16th Mar 2011, 8:56 pm

Quote:

Originally Posted by twocvbloke

bells need tinkering with (they sound uneven, and actually don't sound like the 746 I used to have), but it's ringing anyway, on the linesman at least.

Slacken the fixing screws on the gongs slightly, and with the 'phone connected to the linesman with the ring button activated (you may need more than two hands

), rotate each bell gong for maximum volume - they are mounted eccentrically (i.e. the mounting hole isn't central) so that rotating them moves their edges closer or further from the clapper. When optimum ring is achieved, re-tighten in that position.

AndiiT · 16th Mar 2011, 8:58 pm

Hi,
You need to ensure that links T16 - T17 - T18 - T19 are present in your telephone; in the original wiring link T17 - T18 was provided in the block terminal by linking the Green and White wires together, this was to enable an extension bell to be connected without having to dismantle the telephone instrument, BT52A block terminals used to have the necessary link fitted.

Your incoming ringing problem could be as the result of not having the resistor fitted, but unlikely.
It's more likely that you have a combination of inductive bells and capacitive tone callers on your line that are acting as a notch filter at ringing frequencies - try calling the line with all the phones connected and then disconnecting each one in turn, whilst the line is still being rung, to see if that then brings the bells back to life.

Regards
Andrew

twocvbloke · 16th Mar 2011, 10:12 pm

I've relocated all the appropriate straps/links as per the instructions on britishtelephones, aswell as substituting the link in place of the resistor, so, I can't see how it may have gone wrong?

On the plus side though, I managed to sort out the dial, just took a couple of drops of oil on the gear that connects the dial hub to the governor, and a drop onto the very tip of the governor itself (where it's point meets the cup it's held in), and the latter's made the dial virtually quiet too. The only thing is, I was very disappointed to see it's pretty much all plastic inside there, I guess it's too "new" to have a metal dial assembly, but at least it's running smoothly now.

Inside the phone there's some signs of corrosion on a thing that looks like it has two christmas light bulbs in it (4th pic in first post, to the right of the green thing), I daren't touch it incase it's corroded to the point of detaching, as has happened with some past damp damaged electronics I've had in the past.

Anyway, I'll try the line experiments tomorrow, falling asleep as I type now, so that's for another day.

Tim · 17th Mar 2011, 1:30 am

Looks like a date of 1980 on the base there.
The thread that fixes the cover of the block terminal(BT52) is 4BA I think. It's certainly BA anyway.

gpogal · 17th Mar 2011, 10:19 am

You can get new round profile Ivory BT style line cords with the correct BT 746 colour coding (white,red,blue,green) , complete with spade connectors a grommet and a BT plug at the other end for about £4.50 if you shop around. They look a lot nicer colour matched and having a round profile, rather than flat

SeanStevens · 17th Mar 2011, 10:39 am

I have a bag full of 'dead' 746's. If you need anything specific from a chassis PLMK.

SEAN

russell_w_b · 17th Mar 2011, 10:54 am

Quote:

Originally Posted by gpogal

'You can get new round profile Ivory BT style line cords with the correct BT 746 colour coding (white,red,blue,green) , complete with spade connectors a grommet and a BT plug at the other end for about £4.50 if you shop around.'

This chap is very good - £5.00 minimum order, but grab yourself some other stuff whilst you're on. A line cord is £3.50.

twocvbloke · 17th Mar 2011, 11:24 am

Bit of a random one, but, I was just tinkering with the phone when I noticed a faint buzzing in the earpiece, not normally a problem, but, the phone is unplugged...

However, upon touching my laptop's case, it went away, so I think my laptop is quite electronically noisy...

I just noticed the dial's a tad skewiff, I'll get that sorted though later...

Just looking at the GPO spares link, and am I right in thinking that some of the 746 handset cords were shorter than others? My new 746's seems shorter than what my old Two-tone grey had, or is it just one of those "at time of manufacturing" things?

twocvbloke · 17th Mar 2011, 11:27 am

Quote:

Originally Posted by Tim

Looks like a date of 1980 on the base there.

I was wondering if that was a date mark, kind of makes the seller's story a tad wrong if it is a 1980 phone...

russell_w_b · 17th Mar 2011, 12:26 pm

Quote:

Originally Posted by twocvbloke

'I was wondering if that was a date mark'

Looks like it was made by GEC/AEI at Newton Aycliffe, Co. Durham, in 1980. I think the dial mechanical construction gives the age away to a point.

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

twocvbloke · 17th Mar 2011, 12:37 pm

Newton Aycliffe eh? Funny how things travel about yet seem to come from near to where I was born...

So yeah, I'll be interested to know how that fella had the phone in his house since the 1970s, if it was made in 1980, maybe he's a time traveller....

Line testing has been scuppered today, seems that the nephew (1 year old) MUST stay here for the day, and he's in the "Must grab everything and bash it about" stage, and I don't want that happening to my phone, that and the line must be kept free cos his mother's in hospital...

You know, I've looked at the colour coding for the 3.3k resistor, and I'm sure I have seen one recently about the house, but I have no idea where it was, or if it was part of something I've recently disposed of, or it was seen in part of those "lucky bags" that maplin sells when I was last there, oh well, I've spied a few conversion kits on ebay I might just get, with matching colour cables...

16th Mar 2011, 3:58 pm	#1
twocvbloke Retired Dormant Member Join Date: Oct 2010 Location: Colne, Lancashire, UK. Posts: 527	Unmodified Cream/Ivory GPO 746!!! I got me a 746 again! Now, this one I spotted with the same stall holder in Burnleh a couple of months ago, and it seems nobody wanted it, so today, I handed over £25 (seems reasonable given it's unmodified and in very good condition), and here I am with a classic phone again. I was planning to convert it today, but unfortunately, the electronics shop that I went to for a 3.3k resistor was out of stock of that specific resistor (seems every time I go there for something specific, they never have it in stock, bad luck I guess!), so for now, I shall just give it a wipe down and look at it lovingly. The fella told me he'd had it in his house since 1970, and was in use up until "recently" (given how I'd seen it a couple of months ago, it wasn't that recent!!), it still has the Block Terminal on the end of the cable, but is missing the nut that holds the lid on, and all the wires were disconnected, but reconnecting them all up properly and connecting it up to my linesman phone, and the phone is working great, speech is clear, the bells ring (albeit a tad roughly), so apart from the slow-mo dial (I think that's going to need stripping and lubing), it's perfect. And now some photos (taken with my phone, haven't charged up batteries for my camera yet): Attached Thumbnails

16th Mar 2011, 4:32 pm	#2
twocvbloke Retired Dormant Member Join Date: Oct 2010 Location: Colne, Lancashire, UK. Posts: 527	Re: Unmodified Cream/Ivory GPO 746!!! What a stroke of luck, it still has it's dial label!!! It was just turned over... (there is a number on there, but I thought I best blank it in case it is still actually in use) Attached Thumbnails

16th Mar 2011, 5:23 pm	#5
twocvbloke Retired Dormant Member Join Date: Oct 2010 Location: Colne, Lancashire, UK. Posts: 527	Re: Unmodified Cream/Ivory GPO 746!!! Well, it also needs the dial sorting out, cos comparing it to my linesman phone's dial, dialling 0 showed it rotating slower by about a second, I'm just so pleased I have it, it looks very nice, shame I haven't got a little table by my sofa to put it on...

16th Mar 2011, 8:16 pm	#6
twocvbloke Retired Dormant Member Join Date: Oct 2010 Location: Colne, Lancashire, UK. Posts: 527	Re: Unmodified Cream/Ivory GPO 746!!! Well, done the resistorless conversion, and on my linesman phone with the ADSL filter, it works perfectly, on the phoneline (VirginMedia, in an Ex-Cable & Wireless area which supports Pulse-dial) with one cheap binatone plugged in upstairs where I can't actually access the socket, erm, nowt, ah well, I'll just have to get the resistor, just to finish off the conversion properly. Just that and the dial to sort, not really looking forward to that.

16th Mar 2011, 8:36 pm	#7
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: Unmodified Cream/Ivory GPO 746!!! When you say "nowt", do you mean that it is dead when off-hook or simply that it doesn't ring? If the former, the problem lies elsewhere than the lack of resistor, as this is not even in-circuit when off-hook. I am, however, struggling to think what would be different between linesman and 'phone line - other than possibly line voltage. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

16th Mar 2011, 8:37 pm	#8
twocvbloke Retired Dormant Member Join Date: Oct 2010 Location: Colne, Lancashire, UK. Posts: 527	Re: Unmodified Cream/Ivory GPO 746!!! And a picture, I did the modern-cable-into-Block-Terminal wiring technique, rather than putting a new cable into the phone itself, mainly cos I haven't got a proper matching cable to fit it. And I cheated with the BT, I used a white GEC one I bought off ebay last month, cos the one the phone came with is caked in paint and missing two screws from the inner two terminals, and the nut that the main screw attaches to, and also it seems the screw has fallen out and disappeared too, it's cursed I tells ya! Still, I love this phone, bells need tinkering with (they sound uneven, and actually don't sound like the 746 I used to have), but it's ringing anyway, on the linesman at least. Attached Thumbnails

16th Mar 2011, 8:58 pm	#11
AndiiT Octode Join Date: Aug 2005 Location: Saltburn-East, Cleveland, UK. Posts: 1,786	Re: Unmodified Cream/Ivory GPO 746!!! Hi, You need to ensure that links T16 - T17 - T18 - T19 are present in your telephone; in the original wiring link T17 - T18 was provided in the block terminal by linking the Green and White wires together, this was to enable an extension bell to be connected without having to dismantle the telephone instrument, BT52A block terminals used to have the necessary link fitted. Your incoming ringing problem could be as the result of not having the resistor fitted, but unlikely. It's more likely that you have a combination of inductive bells and capacitive tone callers on your line that are acting as a notch filter at ringing frequencies - try calling the line with all the phones connected and then disconnecting each one in turn, whilst the line is still being rung, to see if that then brings the bells back to life. Regards Andrew

16th Mar 2011, 10:12 pm	#12
twocvbloke Retired Dormant Member Join Date: Oct 2010 Location: Colne, Lancashire, UK. Posts: 527	Re: Unmodified Cream/Ivory GPO 746!!! I've relocated all the appropriate straps/links as per the instructions on britishtelephones, aswell as substituting the link in place of the resistor, so, I can't see how it may have gone wrong? On the plus side though, I managed to sort out the dial, just took a couple of drops of oil on the gear that connects the dial hub to the governor, and a drop onto the very tip of the governor itself (where it's point meets the cup it's held in), and the latter's made the dial virtually quiet too. The only thing is, I was very disappointed to see it's pretty much all plastic inside there, I guess it's too "new" to have a metal dial assembly, but at least it's running smoothly now. Inside the phone there's some signs of corrosion on a thing that looks like it has two christmas light bulbs in it (4th pic in first post, to the right of the green thing), I daren't touch it incase it's corroded to the point of detaching, as has happened with some past damp damaged electronics I've had in the past. Anyway, I'll try the line experiments tomorrow, falling asleep as I type now, so that's for another day.

17th Mar 2011, 1:30 am	#13
Tim Dekatron Join Date: Jan 2003 Location: Bradford on Avon, Wiltshire, UK. Posts: 3,310	Re: Unmodified Cream/Ivory GPO 746!!! Looks like a date of 1980 on the base there. The thread that fixes the cover of the block terminal(BT52) is 4BA I think. It's certainly BA anyway. __________________ "Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."

17th Mar 2011, 10:19 am	#14
gpogal Retired Dormant Member Join Date: Dec 2006 Location: Barnsley, South Yorkshire, UK. Posts: 12	Re: Unmodified Cream/Ivory GPO 746!!! You can get new round profile Ivory BT style line cords with the correct BT 746 colour coding (white,red,blue,green) , complete with spade connectors a grommet and a BT plug at the other end for about £4.50 if you shop around. They look a lot nicer colour matched and having a round profile, rather than flat

17th Mar 2011, 10:39 am	#15
SeanStevens Octode Join Date: Sep 2009 Location: Bath, Somerset, UK. Posts: 1,033	Re: Unmodified Cream/Ivory GPO 746!!! I have a bag full of 'dead' 746's. If you need anything specific from a chassis PLMK. SEAN __________________ There are only 10 types of people, those who understand the binary system, and those who don't.

17th Mar 2011, 11:24 am	#17
twocvbloke Retired Dormant Member Join Date: Oct 2010 Location: Colne, Lancashire, UK. Posts: 527	Re: Unmodified Cream/Ivory GPO 746!!! Bit of a random one, but, I was just tinkering with the phone when I noticed a faint buzzing in the earpiece, not normally a problem, but, the phone is unplugged... However, upon touching my laptop's case, it went away, so I think my laptop is quite electronically noisy... I just noticed the dial's a tad skewiff, I'll get that sorted though later... Just looking at the GPO spares link, and am I right in thinking that some of the 746 handset cords were shorter than others? My new 746's seems shorter than what my old Two-tone grey had, or is it just one of those "at time of manufacturing" things?

17th Mar 2011, 12:37 pm	#20
twocvbloke Retired Dormant Member Join Date: Oct 2010 Location: Colne, Lancashire, UK. Posts: 527	Re: Unmodified Cream/Ivory GPO 746!!! Newton Aycliffe eh? Funny how things travel about yet seem to come from near to where I was born... So yeah, I'll be interested to know how that fella had the phone in his house since the 1970s, if it was made in 1980, maybe he's a time traveller.... Line testing has been scuppered today, seems that the nephew (1 year old) MUST stay here for the day, and he's in the "Must grab everything and bash it about" stage, and I don't want that happening to my phone, that and the line must be kept free cos his mother's in hospital... You know, I've looked at the colour coding for the 3.3k resistor, and I'm sure I have seen one recently about the house, but I have no idea where it was, or if it was part of something I've recently disposed of, or it was seen in part of those "lucky bags" that maplin sells when I was last there, oh well, I've spied a few conversion kits on ebay I might just get, with matching colour cables...