GPO 232 conversion

[steve.w]

I have been delving in my cellar and re-discovered my GPO 323 telephone along with a bell set 41. I had been hoping that the no41 bell set could be used with the 323, but from looking at all the useful websites and advise previously given on here I think I am mistaken, and this bell set may only be useful as an extension bell.
I have also realised that the conversion it had many, many years ago actually left it without the induction coil.
I have found somewhere where I can buy re replacement coil, but I am wondering whether it would be possible to wire this phone in some way to my 300 series phone and utilise the apparatus in this phone.
The 300 (I need to check the exact model, but imagine it is the 310 or 312) has been in daily service for many many years, and has travelled with me to my various homes over the years.
Any advice on the use of the two phones would be appreciated.

[russell_w_b]

Originally Posted by steve.w

I have been delving in my cellar and re-discovered my GPO 323 telephone along with a bell set 41.

Do you mean a telephone GPO 232?

[Nickthedentist]

Ah! I was wondering what a 323 was. Seemed odd that a 300-series needed an external bellset. Mystery solved, I think (probably).

[steve.w]

Hello

Ooops! Yes I am mistaken, it is a 232.
Can I edit the original post, or can I delete it and begin again?

Steve

[russell_w_b]

Originally Posted by steve.w

Ooops! Yes I am mistaken, it is a 232.

I wouldn't worry. We know what you mean... Are you saying you'd like to use your induction coil-less 232 to answer any calls incoming to your 300 series phone, effectively extending dial, bell, handset and switch-hook functionality of your 300 instrument to your 232?

[steve.w]

Thanks Russell.
Yes, I think so, it was just something that crossed my mind. It may be that it just isn't possible, or too complex a job to link the two phones.
Otherwise I believe (and please correct me if I am wrong) I am happy to buy a replacement induction coil, which I think will make the phone useable.
Steve

[russell_w_b]

Originally Posted by steve.w

Yes, I think so, it was just something that crossed my mind

Well, it's possible, but it would involve getting at connections in your 300 series instrument that you might not want to tamper with. The incoming pair would parallel across T3 (B wire) and T1 (A wire) of your 232, as normal, then you'd need to run five wires between your 232 and your 300 telephone:

• T8 of your coil-less 232 to T6 of your 300.
• T5 of your coil-less 232 to T5 of your 300.
• T6 of your coil-less 232 to T1 on the dial strip of your 300.
• T2 of your coil-less 232 to T11 of your 300.

I think I'd be obtaining and fitting a new coil. At least then you'd have a telephone you could use independently without dragging the 300 telephone wherever you go.

[russell_w_b]

I could've sworn I'd written that fifth wire in! Youu'd need a wire from the side of your cradle-switch in your coil-less 232 that DOESN'T go to T2 led to that point in your 300 instrument on the opposite side of the cradle switch to the connection to T11. In other words, where the 30 Ohm anti-quench winding on the ASTIC connects.

[steve.w]

Thank you for the info there, it does sound a little complex and Id end up with a mountain of wiring coming from the 300.
I am right in thinking that if I had the coil on the 232 Id be able to then wire it as an extension phone, just like any other phone?

Steve

[russell_w_b]

Originally Posted by steve.w

I am right in thinking that if I had the coil on the 232 Id be able to then wire it as an extension phone, just like any other phone?

You certainly would! Use a standard BT lead with spades on one end and a plug on the other. Connect as per diagram. If you are wiring it without a bellset, then extend the plug and lead to the terminals in your 232 that follow through.

If your lead colours are different, white goes to pin 2, blue to pin 4 and red to pin 5. That's looking at the plug with the lead towards you, the pins away from you and uppermost, and the detent clip on the right. L to R: 1 N/U and 6 N/U.

If you have a bell attached, you might consider replacing the 3k resistor with a solid link.

[Pellseinydd]

Originally Posted by Nickthedentist

Ah! I was wondering what a 323 was. Seemed odd that a 300-series needed an external bellset. Mystery solved, I think (probably).

The Tele 310 needed an external bellset (Bellset No 41 - usually converted from Bell Set No 1's which were plentiful at that ime!) when used for its original purpose as a 'shared service' separate metering' telephone. The Tele 310 'Call Exchange' telephone was introduced in the late 1940's and needed a relay (in the Bellset 41) to prevent bell tinkle when dialling. However the 310 had a very short life as the 'thermistor' appeared on the scene. Most Tele 310's were converted by GPO Factories Dept, with the thermistor replacing the need for the BS 41. Hence the scarcity of Tele 310's and the number of Bellset No 41's which survived.

I got my mint Tele 310 from an eBay seller in Belgium!