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Blivit42 · 21st Jul 2020, 10:47 am

Hi, I have a 706 telephone that seems to be non-standard.
I had two of these phones that I got from the same person. I tried converting them, one worked, the other didn't. The incoming line went off for a short time, so I assumed there was a short and I started to look for faults and tracing the internal wiring.

It seems to be an early version of the 706 without a PCB. I noticed two odd things.

1) The Automatic Sensitivity Regulator is missing and only the terminals A, C & E are fitted. The 706 phone should work with the regulators reversed, which would connect terminals B, C and D, but since B and D are missing, this won’t do anything.

2) The Induction coil No. 31 is missing and doesn't seem to have ever been installed. Maybe someone has removed it.

There is a wiring schematic N112419/4 pasted inside the cover of the phone which doesn't show the induction coil or the regulator, so I don't think it has been altered. It differs from the wiring shown on standard N806 diagram.

Can anyone tell me what this phone might be and if could be converted? I suspect it may have been a special for an extension, which won't work on its own.

Thanks for any help.

21st Jul 2020, 10:47 am	#1
Blivit42 Diode Join Date: Jul 2020 Location: Woodford Green, London, UK. Posts: 3	Odd 706 Hi, I have a 706 telephone that seems to be non-standard. I had two of these phones that I got from the same person. I tried converting them, one worked, the other didn't. The incoming line went off for a short time, so I assumed there was a short and I started to look for faults and tracing the internal wiring. It seems to be an early version of the 706 without a PCB. I noticed two odd things. 1) The Automatic Sensitivity Regulator is missing and only the terminals A, C & E are fitted. The 706 phone should work with the regulators reversed, which would connect terminals B, C and D, but since B and D are missing, this won’t do anything. 2) The Induction coil No. 31 is missing and doesn't seem to have ever been installed. Maybe someone has removed it. There is a wiring schematic N112419/4 pasted inside the cover of the phone which doesn't show the induction coil or the regulator, so I don't think it has been altered. It differs from the wiring shown on standard N806 diagram. Can anyone tell me what this phone might be and if could be converted? I suspect it may have been a special for an extension, which won't work on its own. Thanks for any help.