Does anyone have a British No3 dial in their collection?
My No3 (below) is in poor condition with missing components. A few good clear photos of the reverse would be of help as a reference (I only have this one reverse side image, below) as the dial needs a disassemble/clean/rebuild.
I have a few dial spares - some components may take a little time to source if specific to the No3 as this dial is hard to find.
Notice mine has a different style fingerstop to that illustrated.
Images below show what mine currently looks like (left), what it should look like (right).
If you have this dial, would you please add reverse side images to this thread.
Thanks.
I have good news and bad news.
The bad news is that the dial is not a No 3 and, as you say, there are parts missing. In particular, the complete governor and the subframe that holds it. Unless the same parts from a No 3 will fit, those parts will be very difficult to find.
The good news is that the dial is not a No 3, it pre-dates the No 3 and reflects the drawings in the patent printed on the finger wheel. The finger stop is correct as is the pulse interrupter.
I have never seen that dial before and I would suggest that few others have either.
Regards
Jack
Quote from: Jack Ryan on February 01, 2021, 07:07:02 AM
...it pre-dates the No 3 and reflects the drawings in the patent printed on the finger wheel. The finger stop is correct as is the pulse interrupter.
I have never seen that dial before and I would suggest that few others have either.
Thanks for the reply Jack.
I noticed similarities to the No1. Had wondered if it might be an early transition (or 'work in progress') dial between No1 and No3.
Might even be an 'elusive' No2... could be this dial just didn't work as hoped for and so skipped production altogether.
Dial No2. Used on test desk.
Dial No4. Never issued.
https://www.britishtelephones.com/dials/dialbrit.html
At the very least I can get this dial cleaned up and looking good from the front. I knew components would be hard to find, but wanted to take a closer look, rescue it, and see what could be done.
Always good to find something a little out of the ordinary.
Any idea where we can find out more info or what No. it might be?
Quote from: FABphones on February 01, 2021, 07:29:59 AM
Thanks for the reply Jack.
You're welcome.
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I noticed similarities to the No1. Had wondered if it might be an early transition (or 'work in progress') dial between No1 and No3.
Siemens Brothers patented a whole series of dials in the UK, Canada and other places. Their efforts were not all GPO centric.
Your dial is a re-packaged Mercedes dial with what appears to be the first incarnation of the mount which the GPO would eventually standardise on. The Siemens patents took two paths with dial development but a direct line can be seen from the Mercedes dial to your dial, then to the No 3 dial. Two additional requirements became apparent:
- a dial capable of generating dial pulses for the SB, WE and AE exchanges used by the GPO and others at the time. This required a pulse cam that was mounted on the main dial shaft.
- an improved method of generating a longer interdigit delay
So Siemens' dial development made an abrupt shift after the No 3 to the No 8. The No 8 dial became the GPO standard and could be used to generate ATM, WE and SB dial pulses. Neither the original Mercedes nor the No 3 could do that.
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Might even be an 'elusive' No2...
No, that was an ATM dial.
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could be this dial just didn't work as hoped for and so skipped production altogether.
I'm sure it worked fine but it didn't satisfy the two requirements listed above.
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Any idea where we can find out more info or what No. it is?
Aside from the patent, no - sorry.
Regards
Jack
Quote from: Jack Ryan on February 01, 2021, 07:56:30 AM
Your dial is a re-packaged Mercedes dial with what appears to be the first incarnation of the mount...
Good to hear.
I'll keep researching, and take a proper look through the patents.
Thanks again.
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If anyone could add photos of the reverse side of their British Mercedes dial, and a No3, that would be appreciated.
:)