746 circuit board with unusual terminals

[Dave Moll]

I opened up one of my 746s today and discovered that its circuit board (shown below) has tags for slide-on connectors instead of the usual. In case it is not legible from the attached image, it bears the markings "419/2/44322/000 ISS [1]". The case has a label reading "617/1/13517/002" and "BLD16 IMP 1" stamped into the plastic"

Having never met a 746 with these terminals before, I am curious whether anyone can throw any light upon this.

[Nickthedentist]

That's truely bizarre, Dave!

I wonder whether it was for made for a private installation rather than the GPO? Are there any GPO markings under the phone itself?

It makes sense though as push-on terminations would be much quicker to alter than screw terminals. Certainly the Statesman, Ambassador etc. had their handset wires attached to the transducers in a similar way.

Nick.

[ThePillenwerfer]

How horrible!

My thoughts are the same as Nick's. I've seen BT ones so late that they didn't have ringing capacitors and the caterpillar diode arrays are made of discretes but even those have proper screws.

- Joe

[dazzlevision]

419/2/44322/000 & 617/1/13517/002
These are Plessey part numbers.

[Dave Moll]

I've not found any markings other than those quoted above. By the way, I realise that I should have said the label and stamping are on the base, rather than the case.

So, at least I now know who was responsible for its creation!

[Nickthedentist]

Interesting, Dazzlevision.

Is the dial label present? Plessey used to do their own, quite different from the GPO/BT ones, see top right here: http://www.britishtelephones.com/diallab1.htm

Nick.

[dazzlevision]

Originally Posted by Nickthedentist

Interesting, Dazzlevision.

Plessey used the same numbering format throughout their businesses. Look at their TV LOPTs and Plessey capacitors (formerly TCC), as examples.

[AndiiT]

Originally Posted by Dave Moll

.... one of my 746s...

Hi,
Does the base of the phone have 746 etc. stamped on it or does it have a model number beginning with N (i.e N1906) ? If the latter this confirms that the phone is indeed a Plessey/Ericsson/GPT/Telephone rentals or whatever they were calling themselves at the time.

As I am sure you are already aware most 706 and746 style phones were manufactured by Erricsson, GEC, Ferranti (Pye) and/or Plessey amongst others. Calling an N1906 a 746 is akin to calling a vacuum cleaner a Hoover.

Regards

Andrew

[Nickthedentist]

Originally Posted by AndiiT

Calling an N1906 a 746 is akin to calling a vacuum cleaner a Hoover.

...albeit a vacuum cleaner that's made in the same factory, from most of the same bits, and looks just like a Hoover

EDIT... just realised that the N1906 is 706-based, but you know what I mean!

[Nickthedentist]

Originally Posted by Dave Moll

The case has a label reading "617/1/13517/002".

Aha!

See http://www.britishtelephones.com/ericsson/03517.htm

Nick

[Dave Moll]

Well done, Nick. That link shows the identical twin of what I have in my possession, except that I don't have a line cord. Like that shown, however, there is no dial label present.

And Andrew, as I have said, there are no markings other than those given in the OP. Do I infer that 617 is the model number?

[AndiiT]

Hi,
I would have said that 617/1/13517/002 is the model number, or at least the Plessey "part number"

I'm not sure why the GPO gave most of their telephone instruments three figure model/type numbers but it might relate to the thinking similar to that for telephone numbers, when it was believed that it would be difficult to remember numbers longer than three digits in length.

Andrew

[Nickthedentist]

I think your theory is right, Andrew.

Who can ever remember Philips model numbers?!

Nick.

[Cobaltblue]

617 is the Plessey location code.

For instance the location codes for Plessey Poole are 666 and 667.

Incidentally Siemens at Poole (formally Plessey) are still using Plessey part numbers.

The second part is usually a single number or two letters.

From my dodgy memory /1/ is a locally manufactured part /7/ is a bought in assembly /HB/ is a Handbook.

The third part is the actual part number 5 digits in length.

The final 3 digits are the variant

Cheers

Mike T

[Dave Moll]

That's really helpful, Mike. So I shall consider the "03517" (which I apologise that I mistyped as "13517" in the OP) to be the nearest thing to a model number.

[Cobaltblue]

Hi Dave

I really wish it were that simple

For reasons not known by me often the part number does not contain the Model number at all.

Sometimes the top level part number will be a part of the 5 digits often the last 3.

This seems to be something the Drawing Office just did its not in the rules of issuing part numbers.

Incidentally as far as I know most of the old Plessey archives have been lost.

Even Plessey Pooles archive is best described as a bit of a mess and that's on a still working (Siemens) site.

I have been trying to locate a list of Plessey sites against location code for some time.

Cheers

Mike T