NB: This thread and the thread: : Norwegian: Elektrisk Bureau 1932-1953 Phones Bakelite versions. http://tinyurl.com/mk4ypt9 (http://tinyurl.com/mk4ypt9) are related.
The Swedish model Norwegian design
This 1920 to 195x made one piece bakelite phone was made with more than this diagram.
This Diagram was the std version made by Ericsson and Elektrisk Bureau of Norway (with different color codes)
dsk
PS
Added picture of the special version used in Trondheim, The handset are probably from another telephone.
DS
I have a rather rare dial from this kind of phone, The type dial has never worked properly.
dsk
The Ericssion dials of that type you can loosen the main gear and advance or retard where the break contacts rest between the gaps in the impulse gear.
Here are 3 alternative diagrams used in Norway inside the same bakelite housing.
They are quite rare, but The Trondheim version may be seen frome time to time, the other 2 ???
I have never seen them.
dsk
Dsk,
As Rdelius mentioned, the pulse cam on your dial rests in the wrong place.
As you probably know, at rest, the pulse contacts should be open. When you begin to dial, the pulse cam moves backwards just enough for the pulse contacts to close. When you release the dial, the pulse cam moves forward to begin the first break and then continues pulsing until it reaches the stop.
If the bursts of AC in your timing diagram indicate a break, it seems that the first break is not only short, it is not completely open (the AC signal is attenuated). Can you adjust the position of the pulse cam and then check for correct operation and cleanliness of the pulse contacts?
Does the off normal contact operate correctly?
What are the details of the dial tester you are using?
Thanks
Jack
Dsk,
Does Fig 28 on the circuit page you posted show a BTMC dial?
Thanks
Jack
The dial in this thread is made by Elektrisk Bureau, Norway, The dials was causing so many problems so E.B. abandoned the production for years, and bought dials from STK (=STC or BTMC)
It is not possible to adjust the timing, and rest positions for the contacts.
The pulse contact had to remain closed in rest position, the other contact was normally open, and closed when moving the dial out of rest position.
dsk
Spanish version seems equal:
(http://www.classicrotaryphones.com/forum/index.php?action=dlattach;topic=11492.0;attach=97548;image)
Similar to the ones I see in Holland, but with one exception. I have never seen a dial like that with 3 wires. Only 4 or 5.
Slightly different wiring on the Norwegian Elektrisk Bureau Chematics:
(http://www.classicrotaryphones.com/forum/index.php?action=dlattach;topic=10196.0;attach=122950;image)
dsk
Big problems uploading pictures, but here is another version of the 3 wire dial:(https://lh5.googleusercontent.com/-FbY4NRdpiaQ/VVBnnKygJKI/AAAAAAAAACY/ly93BBpe6nc/w491-h553-no/1a.png)(https://lh5.googleusercontent.com/-J2T_6lUhwbc/VVBnlRKluzI/AAAAAAAAACU/8BdEHWVLAQw/w491-h553-no/2a.png)
I hope I will be avble to uplod these direct to the forum, now I have made up an Google account for this. :-[
dsk
It looks like SC might have copied elements of this design for their dials
Trying to post pictures re-sized to max length/with (the greatest side) to 1000PX 45 PX/inch
dsk
I think the diagram shows that the dial is actually not that unusual, despite having only a three-wire dial cord.
If the diagram matches the phone, the dial itself actually has five contacts, two for the dial pulse, and three for a break-make switch. It just has two jumpers across some contacts, and it is the specific application or wiring in the instrument that only requires three wires. I only uses the off-normal make contact to shunt the entire phone during dialing, which is what the first dials by Western Electric did too, before the 50AL desk stand with the No. 2 dial.
The 2 dials over are different in the way they make the breaks. The upper has a cam with 10 teeth. the other has a geared moving contact breaker with 2 or 3 breaks pr revolution.
dsk
2 versions of wiring diagrams: Especially made for Trondheim (city) telephone company, and Bergen (city) telephone company.
dsk
I Guess I will Rename this most common circuit to "RIKS Koplinga" RIKS for the rikstelefon or mother company in Norway quite equal to Ma Bell in the US.
Rikstelefonen/Telgrafverket/Telegrafvesenet/Televerket was the state controlled company serving much of Norway, and almost all long distance lines. They used this schematics as standard on both metal and bakelite telephones from the 1920-ies to the "new" circuit came in 1953. Eveven when they were a part of the same company, Oslo, Bergen, Stavanger and Trondheim cities used their own versions.
dsk
After years of looking, I found the last schematic version of the Norwegian 1922 Telephone: The Stavanger circuit "Stavangerkoplinga" And not only that it has a ground button witch is rare, and a dial with number-ring, a version I never have seen nor heard about.
dsk
dsk - how many different circuits were used on phones in Europe?
Quote from: HarrySmith on January 16, 2018, 02:45:16 PM
dsk - how many different circuits were used on phones in Europe?
I do not have a clue, sorry! In my head, German phones had approx the same circuit as the Siemens W48 from 1928 to will in to the 1970-ies, pretty related to what I have named Televerkskoplinga among the circuits used in Norway from 1932 to 1953 (bridge circuit). Still many Norwegian phones had a compensation circuit close to what we know from W.E. 332. This was common in many other European phones especially those from Antwerp. In Sweden they used the bridge circuit who developed to be pretty complicated in the 60-ies. The British do always have their own solutions, and those circuits used from the pyramid and to much later was complicated variants who may be a mix of bridge and compensation circuits. The reason for nominating my phone was what I found so fascinating that engineers in "smaller" towns did choose their own variants in a small country as ours.
dsk