GPO Dial Number 12 - UK Vintage Radio Repair and Restoration Discussion Forum

Mikey405 · 3rd Mar 2024, 5:30 pm

Hi all.

I'm not sure if I've ever actually posted in this section before (then again I have a terrible memory so perhaps I have). Anyway...

I've been cleaning up an old GPO telephone dial number 12 and I have a question for the experts. When dialling, should the governor be engaged as I'm moving the fingerboard round clockwise to select a number?

Obviously it should be engaged when I remove my finger and let the fingerboard return anticlockwise, but it feels rather "odd" to have the governor slowing down the action of my dialling when I'm actually dialling a number.

I've dismantled the whole device to clean it all up but I can't see anything like a one-way clutch that might disengage the governor as I'm dialling - so perhaps that's just how it is.

Many thanks all.

Kind regards.

From Mike.

https://www.britishtelephones.com/tel%20auto%20b5125.htm

Nickthedentist · 3rd Mar 2024, 5:35 pm

No, Mike, it should slip away as you pull your finger around towards the stop. This is the clutch.
This one was rather rusty but I got it working in the end.

Nickthedentist · 3rd Mar 2024, 5:39 pm

If it’s seized, a soak in penetrating oil may help. Or you can replace it. Even one from a 1980s BT 746 or similar will drop straight in.

Mikey405 · 3rd Mar 2024, 5:40 pm

Quote:

Originally Posted by Nickthedentist

No, Mike, it should slip away as you pull your finger around towards the stop. This is the clutch:

Aaaah. Thanks Nick - That would make sense. So I may have a seized clutch then... Is it a one-way clutch? I assume so.

Nickthedentist · 3rd Mar 2024, 5:42 pm

It’s worth doing a full stripdown, clean and oil if you can!

Nickthedentist · 3rd Mar 2024, 5:43 pm

Quote:

Originally Posted by Mikey405

Quote:

Originally Posted by Nickthedentist

No, Mike, it should slip away as you pull your finger around towards the stop. This is the clutch:

Aaaah. Thanks Nick - That would make sense. So I may have a seized clutch then... Is it a one-way clutch? I assume so.

Yes, just a simple coil spring at its heart though.

Mikey405 · 3rd Mar 2024, 5:47 pm

Brilliant! A few squirts of Mykal 67138 (ultra thin oil / contact cleaner) and it's working like a charm. I tried that before but I didn't give it enough of a turn to "break the seal".

Thanks Nik. Much appreciated.

Kind regards.

From Mike.

Mikey405 · 3rd Mar 2024, 5:52 pm

Quote:

Originally Posted by Nickthedentist

It’s worth doing a full stripdown, clean and oil if you can!

All now stripped down completely and soaking in a small vat of white spirit.

Nickthedentist · 3rd Mar 2024, 6:08 pm

Good man! Let us know if you have any probs on reassembly

3rd Mar 2024, 5:30 pm	#1
Mikey405 Octode Join Date: Jul 2006 Location: Solihull, West Midlands and Beaford, Devon Posts: 1,626	GPO Dial Number 12 Hi all. I'm not sure if I've ever actually posted in this section before (then again I have a terrible memory so perhaps I have). Anyway... I've been cleaning up an old GPO telephone dial number 12 and I have a question for the experts. When dialling, should the governor be engaged as I'm moving the fingerboard round clockwise to select a number? Obviously it should be engaged when I remove my finger and let the fingerboard return anticlockwise, but it feels rather "odd" to have the governor slowing down the action of my dialling when I'm actually dialling a number. I've dismantled the whole device to clean it all up but I can't see anything like a one-way clutch that might disengage the governor as I'm dialling - so perhaps that's just how it is. Many thanks all. Kind regards. From Mike. https://www.britishtelephones.com/tel%20auto%20b5125.htm __________________ G7TRF

3rd Mar 2024, 5:35 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 18,219	Re: GPO Dial Number 12 No, Mike, it should slip away as you pull your finger around towards the stop. This is the clutch. This one was rather rusty but I got it working in the end. Attached Thumbnails Last edited by Nickthedentist; 3rd Mar 2024 at 5:40 pm.

3rd Mar 2024, 5:39 pm	#3
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 18,219	Re: GPO Dial Number 12 If it’s seized, a soak in penetrating oil may help. Or you can replace it. Even one from a 1980s BT 746 or similar will drop straight in.

3rd Mar 2024, 5:42 pm	#5
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 18,219	Re: GPO Dial Number 12 It’s worth doing a full stripdown, clean and oil if you can! Attached Thumbnails

3rd Mar 2024, 5:47 pm	#7
Mikey405 Octode Join Date: Jul 2006 Location: Solihull, West Midlands and Beaford, Devon Posts: 1,626	Re: GPO Dial Number 12 Brilliant! A few squirts of Mykal 67138 (ultra thin oil / contact cleaner) and it's working like a charm. I tried that before but I didn't give it enough of a turn to "break the seal". Thanks Nik. Much appreciated. Kind regards. From Mike. __________________ G7TRF

3rd Mar 2024, 6:08 pm	#9
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 18,219	Re: GPO Dial Number 12 Good man! Let us know if you have any probs on reassembly