Telephone 8746. Conversion to work on French telephone system.

[kentplums]

I've got two 8746's and would like to know if there is a definitive and simple way to convert to a 2 wire plug for French type socket.
Thanks in advance

R

[Dave Moll]

I would have thought that reverting to the wiring given in diagram N846 should have the desired effect.

[julie_m]

If they are still using those large 8-way connectors with a central plastic piece in France, they are wired as a 3-wire circuit with parallel bells, as per UK practice -- it could be the top right hand two for the line and the top lft hand one for the ringing, but it was a long time ago and I've forgotten the exact wiring.

If the advent of ADSL has led them to start using RJ-11s, which seem to be the new worldwide standard for phone connections, just wire the phone as per diagram N846, and the middle two pins of the RJ11 are the line.

[kentplums]

Thanks for that info

By the way, the French system is now a 6 connector socket in an inverted "T" shape plug using only the top left 2 connections ( of the inverted "T").
I'll try to get my head round this - can't be too tough can it? Not done phones before!

R

[dagskarlsen]

You may buy youselves out of the problem:
One like this:
http://www.ebay.com/itm/RJ11-US-to-B...item23205a784c
and one like this:
http://www.ebay.com/itm/Adapter-fur-...item27c5ef4d61
will do the job.

On the other hand the splitting from French 2 wire connection to UK 3 wire is only a capacitor. This could easily fit inside the phone and if its not there already, it will cost you far less.
http://www.ebay.com/itm/2pcs-WIMA-Ca...item232da2fe90

All these links are results of a quick search, and you may save money of doing a better search.

dsk

[kentplums]

Well I've done as advised (circuit diag) and got dialing out and incoming working fine - thanks. The one I've used first (slightly earlier with plastic base) doesn't have any bells in it though...fine for an extension (and not too noisy..)
Cheers
R

[kentplums]

....and here it is...

[kentplums]

Much, much later.....

I've wired my second phone the same as the first and all works fine except no bell-ringing despite the full complement of bells and hammer. Any suggestions please?
Cheers
R

[julie_m]

The French phone system used to (back in 1994, at any rate) use a separate ringing wire like the British system. Try inserting an ADSL filter, which ought to regenerate the ringing signal.

Do you have continuity from the "ringing" pin, via the bell coils to the "common" pin?

Do you see an AC voltage between these two points on the wall socket, when the phone is ringing?

[kentplums]

Thanks AJS
looking at the schematic mentioned above, where would I find ringing and common pins? sorry if this is blindingly obvious...
Cheers
R

[OscarFoxtrot]

Bell circuit should be from A wire - T18-17-16 - bell solenoids - T4-5-6-7 - ringing capacitor - T8-9 - B wire

To rewire as for UK use with separate ringing wire:

Remove strap T6 - T7.
Remove strap T4 - T5 and replace with 3.3k resistor
Insert strap T5 - T6.
Red wire of line cord to T8 (B wire)
Blue wire of line cord to T6 (Ringing wire, condensered from A wire)
Insert straps T16 - T17 - T18 - T19.
White wire of line cord to T18. (A Wire)
Green wire of line cord to T15. (earth, not usually used)

[kentplums]

Much obliged...something to be getting on with over christmas.
Cheers
R

[julie_m]

Originally Posted by kentplums

where would I find ringing and common pins?

I'm afraid I don't know the terminology or pin numbering scheme used in France. But in the UK, the line comes in to pins 2 and 5 of the master socket; and a capacitor is fitter in the master socket, between pins 2 and 3. So pin 2 is "voice", 3 is "ringing" and 5 is "common".

You'll have to find some local literature relating to phone socket wiring, for descriptions of the actual function of each socket pin. But the French system seems to be similar to the UK system, with one ringing capacitor for all phones.

[AndiiT]

Originally Posted by kentplums

.....I've wired my second phone the same as the first and all works fine except no bell-ringing...

If you have wired the second phone as a "two -wire" device", it's possible that there is no ringing capacitor present on the transmission board particularly if the phone is a "true" 8746 i.e. not one that has been "cleaned up" at one of BT's factories. Some later transmission boards didn't have C1/2 fitted after the introduction of the 1982 plug and socket system in the UK.

If you know which two pins of your French socket carry the line pair, personally, I would just wire any vintage phone as a two - wire device which in the case of your 8746 (assuming a ringing capacitor is present on the transmission board) would be wired as follows -

Strap T16 - T17 - T18 - T19

Strap T4 - T5 - T6 - T7 (if the bell motor is 4K, if bell motor is 1K substitute Strap T4 - T5 with a 3K3 resistor)

Strap T8 - T9

Line A leg to T18

Line B leg to T8, ensuring that the orange wire from the dial also goes to this terminal.

If there is no capacitor in the C1/2 position you can always add a 1u8 or 2uF one between T7 and T9

Regards

Andrew

[kentplums]

Thanks Andrew -eventually got round to this. Bizarrely the phone rings before the other extension (by about one ring) and is very feeble. In the UK this phone could be heard for miles around. Maybe that's an improvement! Just for interest's sake how could the ring be boosted?
Cheers
R