GPO 706 Field Trial Phone

[FABphones]

I adore 706 phones. If I'd have seen that auction I would have bid bid bid. Lucky you!! Love it.

I would bet good money that the chevrons were luminous. What is the base plate made from?

[Hotline]

I adore 706 phones. If I'd have seen that auction I would have bid bid bid. Lucky you!! Love it.

I would bet good money that the chevrons were luminous. What is the base plate made from?

Thanks!

I am not sure if the chevrons are luminous, I will check tonight and report back.

The base plate is plastic, like MK1 706 phones.

[twocvbloke]

That would be an interesting development if the chevrons had a glow to them, like a precursor to the trimphone's tritium tube dial...

[FABphones]

... I am not sure if the chevrons are luminous, I will check tonight and report back.

I think any glow would have long gone by now. Might get a low reading on a Geiger Counter though, I don't know, I 've never had one to try. Did I mention how lucky lucky lucky you are to have that in your collection? Soooo wish I had one.

Brilliant find   

[Hotline]

I think any glow would have long gone by now. Might get a low reading on a Geiger Counter though, I don't know, I 've never had one to try. Did I mention how lucky lucky lucky you are to have that in your collection? Soooo wish I had one.

Brilliant find   

There is no glow, not sure if there ever was!

Thanks very much, I was lucky to get it. When looking at the eBay listing I thought I could just make out the Field Trial stamp in the pictures but was not 100% sure so I asked the seller what markings were on the phone, when it came back with "Field Trial" I knew I had to have it and got it for a good price too! 

[FABphones]

Is this what you have?

I've found out that this style of chevron was the first dial plate chosen for the 706 phones. At first glance the plate looks metal on this photo but most likely is grey plastic. (?)
The phones I've seen with this had the metal finger wheel.

[Hotline]

Thanks for your interest in my phone.

The dial plate that you have posted is from early non-GPO 706 phones that had a type 12 dial and I think is made of metal, from previous discussions on here I don't believe it was actually found on any GPO supplied 706 phones. The early GPO supplied 706 phones with a type 12 dial had a metal dial plate with black numbers on a white background.

My field trial 706 has a plastic dial plate in gold with raised effect chevrons, the chevrons are embossed into the reverse and not actually raised when felt from the front. I attach some photos below, the last 2 photos show it in comparison with a 746 dial plate, apart from the embossed chevrons, the moulding looks identical.

[andy1702]

Interesting things happened to 706's in 1963. It's the time they switched from Diakon to ABS for the cases. It's also about the time they switched from blank finger plates on the dials to those with the painted chevrons. By the way, those were always painted on the back of what was actually a clear plastic part, the same technique as the correct alpha-numeric dial bezel. Anything screen printed on top of coloured plastic is a modern repro and would not have met GPO specs regarding wear and tear.

I think this phone is a trial when theyw ere doing away with the blank finger plate because Ericsson adopted these very same '3D chevrons' for all their privately issued 706 clones, which had dial 12 to start with but were fitted with dial 21 on later models.

I'm not sure about the clear finger wheel. I've got a big stock of these and there are a lot of differing thicknesses and slight design changes for different manufacturers. Eg some have a central hole for a countersunk machine screw and others have a hole for a screw with a flat back. That's why so many of them get cracked. So I think the thickness is a red herring.

My guess, which is only an educated guess, is the field trial was the chevrons and the clear finger wheel is a later replacement. I can't imagine them trialling a clear part that would fit all phones then going back to having loads of different coloured ones for the production model. However... they have made a saving on this trial with one colour finger plate to suit all, so maybe they DID try a clear finger wheel to suit all too. The mystery is, if that's the case, why did they switch back?

[Hotline]

Thanks for your post Andy.

I think the clear fingerwheel is original to the phone, I know what you are saying about the thickness of them varying and I agree, but I have never seen one like this before, it just feels heavier than others and it only has one small locating hole for the dial mechanism, all other clear fingerwheels that I have seen have 2 small locating holes for the dial mechanism (one above the screw hole and one below the screw hole).

Also, I think it would make sense to have a clear fingerwheel to show off the light gold on the fingerplate.

Sometimes when I take an old phone apart, they just feel correct/original and not messed about with, that is how this phone feels to me - but I may be wrong! 

What is a mystery to me is why the plastic case would also need to be stamped with "Field Trial", but maybe that's what they did with field trial phones.

[andy1702]

I wouldn't be surprised if the case is also made from something non-standard. 1963 was the change over from diakon, so they were probably trying things out. It looks like diakon though.

I'd say your next move should be to have a closer look at the dial.See if you can find a date on it. If it doesn't match the phone then there's a good chance it's not as original as it looks.

The problem with these phones is it's so easy to swap parts over that finding out what was truely original is a tital nightmare. Assuming this is original though, I wonder why they didn't continue with it, only to go back to the clear wheel years later?

[Hotline]

Hi Andy

The case is not Diakon as it has suffered from minor discolouration.

All the plastic parts have a small circle with a line though it embossed - case, handset, earpiece and microphone caps - this can be seen in the photos of my original post.

The dial is dated 1963 in line with all the other components in the phone.

The phone has "Patents Applied For" printed on the rocker assembly, this is something I have not seen before.

I wonder how many of these Field Trial phones would have been issued.

[Hotline]

I have just bought another field trial 706 in ivory on eBay, it looks identical to the one I already have, but dated 1964 rather than 1963. The handset appears to have been replaced with a topaz one at some point though.

Not bad for £8.50 plus postage!

I will post some detailed photos when it arrives 

[ThePillenwerfer]

I saw that and wondered if the body was Diakon but the handset ABS and only the latter had discoloured with age.

[andy1702]

Have we worked out what these phones actually are yet? I can't get past the thought that if they are field trials from around 1963, why did they then discontinue them and go back to the expense of different coloured dials, only to finally take up the univeral clear dials in 1967 with the release of the 746? I think there's something we're not getting here, but I don't know what it is.

I'll be interested to know if this one says field trial anywhere on it.

The other option is that the first one is a 1963 phone that went back to the factory as a 'wipe up' later and then became part of a field trial, fitted with the new dial.

Just for the record... those '3D' arrows on the dial 12s (as used by Ericsson) are not metal. The dial plate is made of the same plastic as the later flat 3D ones used with dial 21. Both have the arrows carved into the back and are then back painted with the same silver paint as used for the background on the standard dial 21 as fitted to every 746.

Does this new one have a dial 12 or a 21? If it's a 21 you might get lucky and see it marked something like 21C, which would indicate it should be a coloured dial. That would help solve the mystery.


EDIT: I think I may have worked this out! Can you post a photo of the bottom of the new one please? If I'm right it will be another with a plastic base. I'm off to do a bit of research, but I'll be back! 

[andy1702]

OK, so I've done a bit of research and here's my theory as to what these phones are...

The first clue is in the photo of the base plate of the first phone. The code 706L E63/1 tells us this is a 706 with an alpha-numeric dial surround with traditional wiring made in 1963 by Ericsson. This is confirmed by the fact that Ericsson liked to give all their component parts a part number beginning with the letter 'N'. The 10th photo down the thread clearly shows the bell coils with the marking 'N50433C' on them, which seems to be an Ericsson part number.

Now, Ericsson were well known for producing their own version of the 706, known as the 'Etelphone'. They can usually be identified by a model code beginning with either N1900, N1901, N1340 or N1341 cut into the plastic base. Other than that they are pretty much identical externally to a 706 and very similar internally too. This means there is a lot of part interchangability. The Ericsson 'clones' as we'll call them can normally be distinguished by a number only dial surround, but take a look at this page  http://www.britishtelephones.com/ericsson/n1900.htm and you'll see three small colour photos of N1900s all with the GPO standard alpha-numeric surrounds. They are definitely Ericsson phones in the photos, because the red one had a bright metal carrying handle, which was never supplied on GPO phones.

We know a lot of early N1900's used up a supply of the old dial 12. But later examples had dial 21, normally with plastic finger wheels of one type or another.

So here's my theory... perhaps ericsson were ahead of the design game in 1963/4 and had the idea for the clear finger wheel? The GPO specified coloured dial components at the time, but maybe they did a trial using Ericsson phones with standard Ericsson 3D dial plates and the new clear finger wheels as a cost saving experiment in not having to produce all those coloured parts. At the time the GPO didn't go any further than the trial and reverted back to coloured dials, but now with printed arrows on the dial plates, probably inspired by the Ericsson 3D ones.

While coloured dial 21s with Ericsson inspired printed arrows became standard for the GPO, Ericsson decided to start using their new clear finger wheels on their N range of clones, rather than the previous expensive stainless steel ones. The GPO then finally changed their mind and adopted a similar clear finger wheel across all their manufacturers in 1967 with the release of the 746, also adopting the 'light gold' (which always looks like silver to me) as the background to the new numeric dial plates created for the 746.

So what I think Richard has here are two genuine telephones, which were supplied by Ericsson as part of a field trial around 1963-4 to test dial finger plates and finger wheels that would not have to be produced in a range of colours. For whatever reason the test seems to have been a failure, but the GPO finally decided to use the plastic finger wheel three years later on the 746. That would explain why these prototype Ericsson finger wheels are a bit different.

All of the above is an educated guess, going from what I know from my own collection of 706s and ericsson clones, plus various photos used in publicity material at the time. I could be wrong, but it seems to be the only logical conclusion given all the available facts.

Can we find anyone who worked for Ericsson at the time to confirm this?

Andy.