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new GPO 706 two tone

Started by Tom B, March 17, 2011, 06:07:11 PM

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gpo706

You want a pic of a boring black set? LOL

Not at the moment Tom, my computer runs off a disc, and moby cant talk to it yet, I will post some when I get all this "modern" tech fixed.

(Restoring a phone is a dawdle compared to these accursed computers).
"now this should take five minutes, where's me screwdriver went now..?"

Tom B

Tom

GG



Yo GPO-  Thanks for the referrals, I knew about GPOSpares but the others are new to me.  Gotta' put together an order soon.

Owain-  TR Services in New York: Aha, so that explains the 706s I saw all over a department store when I was a little kid.  I remember seeing these phones in "the weird colors that didn't match," with "the cords coming out the back" and "that odd logo above the cords" (the Ericsson Telephones Ltd. logo that looks like a circle divided in thirds).  I didn't know it was TR that was responsible for these. 

About 25 years ago I used to get 706s from another branch of TR, mostly stuff they were offloading one way or another.  These were PAX phones minus induction coil and plus an interesting circuit with resistors & capacitors instead.  They have a clear crisp sound to them, so I have no complaints.  Most of them ended up in installations for clients; I kept a handful in various colors.  Most of them have numeric-only dials.  A few have alphanumeric USA markings, two of which are metal base versions with induction coil etc., NOS.  A couple are 746s originally in black, NOS, one got converted to red by me; I still have all the orig. parts. 




gpo706

#33
Here's the pics of the case replacement unit (black) and the matching watch receiver (comes without the mounting hook but the seller says they as like hen's teeth, hence him not selling his).

I splashed out ten sheets on the light blue repro body for one of the scabby 706's - its not a standard issue GPO colour, so why buy it?

Well I had already got a light blue armoured handset for one of my 745's, which ebay has lost the picture for, apologies...

There's the same coloured handset in the link below.

http://www.britishtelephones.com/t745.htm

which wont fit the handset aperture so why not try and use it on this new case?

This is a radical departure for me, usually I had stuck to "as issued" colours being a bit of a purist but if if it gets another of these scabby 706's looking nice I have reconciled myself to a bit of adaptation, I'm expecting it will look really pretty with the light blue new case and the handset.

But what dial surround and fingerwheel to get, Concorde blue might work?
"now this should take five minutes, where's me screwdriver went now..?"

bingster

Did they make these in Balmoral blue, or was that strictly for the Jubilee Compact?  Those two colors would make for a nice combination.   A Topaz ring would make for a nice Eastery look, too.
= DARRIN =



gpo706

#35
Hi Bingster,

Don't know what difference there may be between "Balmoral blue" or "Concorde blue" which was a standard 700 series colour, this light blue never was excepting in payphone handsets I would imagine.

(PS - Concorde blue fades to a mellow dark green after years of sunshine, so your spares hardly match).

Seems there is plenty of kits being issued (remade) in new colours, but they all seem to be in combinations of the two - eg light grey/ivory, seems if you want a matching set you have to buy two kits and swap the bits.

I have a discarded "Concorde blue" dial fingerwheel and a fingerplate surround in the spares box so that might do the trick, but I'm no interior designer, although I've seen one on TV...

"now this should take five minutes, where's me screwdriver went now..?"

Tom B

Scot - Put the Concorde Blue dial ring and fingerplate on the new blue body and let's take a look at it. ;)
Tom

Tom B

Adding to the 706 stock - I just won this beauty on eBay for £17.99 ($29.00) inc. postage.
Tom

gpo706

That's a nice set, chevron backs and all.

I'm finding it weird I have ended up with more 706s than 746 in my pile?
"now this should take five minutes, where's me screwdriver went now..?"

Tom B

I like the 706 better, so for me you're on a winner so far ;D
Tom

gpo706

I had returned to the charity shop http://www.hospicesofhope.co.uk/ a few weeks ago and offered the girl behind the counter a swap for the scabby 8746 they used at the till, and which the other guy complained about, a swap for a DTMF.

She wasn't interested, said it wasn't for sale and was still being used at the till-point, I walked out much deflated by my rebutted proposal.

Today was out "poundland" shopping and popped into the shop again, the phone had vanished.

So I asked the lass (different lass), where it had gone, she said "oh it's over there on the shelf..."

It was on a wee dinky shelf all on its own mounted on a wallrack, you wouldn't have seen it it was 6ft up, how much?

8 pounds and fifty pence.

Done deal!

Its the third 8746 the shop had, (missed the first one) this is an 8746G DFM 82/2.

"now this should take five minutes, where's me screwdriver went now..?"

Wallphone

Scot, What is special/rare about a 8746? I looked it up and it says that it is a 746 that has been modified for plug & socket. Does that just mean you can plug it into the wall socket? If so, then I take that to mean that phones were hard wired to the outlet before this?
Doug Pav

Stephen Furley

#42
When the plug and socket system was introduced certain existing models of telephone such as the 746 and 786 (DTMF version of the Trimphone) were produced in plug in versions.  To distinguish these from the original hard-wired versions a '8' was added to the start of the model number, e.g. 8746 and 8786.  I have a 8786.  Older existing telephones could be converted.  The conversion involved moving a few links and wires on terminals inside the telephone because the plug system used a bell capacitor inside the master socket, rather than in each telephone, adding a resistor in series with the existing 1000 Ohm ringer windings to reduce the REN of the telephone to 1, (new telephones had 4000 Ohm ringers), adding a rectifier element 205 (a pair of diodes to avoid acoustic shock) across the receiver if not already fitted, and of course fitting a new line cord with a BT type plug on it. Note that on the BT system the line is on pins 2 and 5, not 3 and 4 as on a RJ11.  Pin 3 is for the bell wire, and 4 is for an earth where one is required, mainly for recall on some PABX systems, though it was also used for shared service at one time.

It was intended that a left-handed version of the BT plug, I can't remember the number, would be used for handset cords, but it almost never was; I have two telephones which do use it.  Almost all modern telephones here use the same modular connectors as most of the rest of the world, 6 position for line cords and 4 position for handset cords.  This means that the line cord has to have a RJ11 on one end, and a BT plug on the other.  Remember that on the BT plug the line is on 2 and 5, and on a RJ45 it's normally on 3 and 4.  This means that on telephones for use in the UK either the line cord jack on the telephone has to be wired differently to it is just about everywhere else, or the wires in the line cord have to cross over from one pair to the other inside the plug.  Unfortunately, both systems are used, so a line cord from one telephone may not work with another, even though they look identical.  At work, our two most common analogue telephone models use line cords wired differently, so when replacing a faulty telephone I often have to replace the line cord as well, which often has filing cabinets etc. on top of it which I have to move.  To add to the confusion, two different organisations decided to number the pins in reverse directions, so 6 becomes 1 etc.  This means that in documentation plugs and jacks often have reversed numbering.

Another problem with the BT system is that the single, unbalanced, bell wire, when taken to extension telephones around the house tends to function as an antenna, feeding interference into ADSL systems, greatly reducing the possible data rate.  I increased by speed by about 60% when I fitted a filtered faceplate.  This filter is to remove noise from the ADSL signal, not to be confused with the filter to remove the ADSL signal from telephones.  Most new 'phones in the UK now will ring on a simple two wire line, and don't need the bell wire, but most older ones will not, and do.

Adapters are readily available to plug a BT type 'phone into a RJ11 modular jack, but these exist in two versions, one with a bell capacitor, and one without.  If you use one, and the 'phone won't ring, then you've probably got the type without, and you need the type with.

GG



What it looks like from this side of the pond:

BT modular plugs & jacks appear to be more robust than RJ-11, with larger contact surfaces and with a tab that appears less likely to break off than ours.

Where I think BT went wrong was with capacitors in sockets and all that stuff: it would have been simpler to have one capacitor in each phone, with a bias spring on the bell, and then wire extension phones in parallel with no series element to the circuit.  The retrofits to obtain that result would have been easy.

But we have our own screwy wiring in the US too. 

The most frequent thing is when different wiring contractors use all data jacks throughout a building, and then wire them to different standards: T-568-A vs. T-568-B.  In that case, what would ordinarily be the 2nd pair on an RJ-11 jack, comes out as different pairs on the two different wiring plans for data jacks.  This has led to much confusion and merry chaos on more than one occasion.


Owain

Quote from: GG on September 11, 2011, 11:58:31 PM


Where I think BT went wrong was with capacitors in sockets and all that stuff: it would have been simpler to have one capacitor in each phone, with a bias spring on the bell, and then wire extension phones in parallel with no series element to the circuit.  The retrofits to obtain that result would have been easy.

On the 'new plan' socket system the phones are wired in parallel.

The capacitor and a test resistor in the master socket mean that, even with no phones plugged in, there is always a circuit across the line for testing purposes.

The master socket capacitor was seen as necessary to prevent bell tinkle on loop disconnect dialling. I don't think the GPO has ever used bell bias springs.