Etelphone N1900 (was Tele 706 MK1)
Isn’t it a lovely colour! It could do with a bit of a clean, and the mic side of the voice bridge doesn’t seem to work properly (despite me swapping out the mic element) – and various bits of it aren’t original – but it’s interesting for other reasons.
Feel free to wander off if you’re not as into the phone thing as me ;-)
I bought this GPO 706 Phone off ebay, as I’ve been looking for a 706 MK1 for a while and I noticed that this 706 had a metal dial (which appears to be a “Dial No 12“) so stood a good chance of being a MK1, possibly an early one at that.
Taking the lid off shows that it is a MK1 (the MK2 had a PCB) but there’s something odd about it.
See that slot in the middle? It should have a circuit board mounted vertically in it. Not only is the rectifier board missing, so are the middle three contacts. A close look at the socket seems to suggest they were never present. The way the large resistors are mounted seems to reflect that. It doesn’t really match the N806 diagram, although I did notice one thing that’s interesting.
The N Diagram, Page 1, Note F says:
Early issues have dial brown connector connected to gravity switch spring 4 instead of T3
Which this phone does have. It matches Note F and has a Dial No 21 – so I think it probably is an early MK1.
Another clue that it’s probably an early model is that it’s got a paster diagram inside the case. Now, I’m only guessing here because I can’t find any references that would say yes/no on the paster diagram thing but none of the other 706s I’ve seen had them, but they were all MK2s.
The paster diagram is labeled N98293, but I can’t find any reference to an N diagram of that number online, but I assume the paster diagrams are numbered differently. The paster does match the wiring of the phone more closely than N806 does.
So, this is proving to be quite an interesting ebay purchase!
I’m not 100% convinced that the brown handset and the dial surround are original (I think the green 706s had dark green handsets) and it’s possible that this phone is early enough to have originally had a braided handset cord. I suppose that the paster diagram is probably the real key to working out how this phone was originally configured.
Update – 2010-02-12:
I found a number stamped on the baseplate, it says N1900E69 which means that the phone was built by Ericsson, and is an N1900, or “Etelphone” although some of the details still don’t match. So there’s a bit more digging to be done yet!