Gray Euro Phone??

[Doug Rose]

Anyone know what I have here?? It little and light. Fully functional, screw in clear area in back release the shell. Took me a while to figure that out!!  Different letters over the #9...Doug

[unbeldi]

This looks like a Swedish Dialog set.  It was the standard set of the 1960 and 1970s there.

Ericsson Review  41(4) p136, April 1964, DIALOG-The New Telephone, etc.

[Doug Rose]

thanks Karl...Doug

[dsk]

The dial letters indicates Danish.   Sweden use 0 at 1 pulse.

dsk

[Doug Rose]

thanks dsk...I appreciate the info....Doug

[Alex G. Bell]

The dial letters indicates Danish.   Sweden use 0 at 1 pulse.

dsk

I have a Danish KTAS "grab-a-phone" style set with these same markings on a spring loaded white enamel plate.  The plate is flush up against the back of the finger wheel until a finger is inserted to dial, pushing the plate back.  It's one of the more interesting dial variations I've seen. 

The lack of depth between the finger wheel and plate gives the phone a somewhat unreal appearance. It's hard to describe the effect, but essentially the dial seems 2 dimensional and very obviously so, not a subtle effect.  Of course the plate rotates with the finger wheel like a WECo domestic #1 or European 7001 dial.

Mechanically the dial is a modification of a British dial which KTAS bought from Britain.

[dsk]

I found this Danish wikipedia:  https://da.wikipedia.org/wiki/KIRK_telecom  and this youtube (English) https://www.youtube.com/watch?v=tuZU9xtBF4o
dsk

[dsk]

The Ericsson Dialogue telephone was made under licence in many countries.  Most countries used identical circuits as yours, and the dial was the same with or without lettering depending on local standards. 

Of course we could not keep everything as standard here in Norway, so our had different caps on the handset, with dynamic transmitter and receiver elements. (identical elements) The transmitter were also acting as a loudspeaker for the electronic ringer signal.  With this setup you needed a totally different circuit so it had a complex hookswitch, and 2 of those new expensive transistors for use as a amplifier of the transmitter.  In on-hook position one of the transistors made a howl 2500 Hz mixed with the ringing frequency making a warbling whistle.

Of course we had to use another dial with the mechanism equal to what the BTMC or Antwerp telephones used from about 1930-ies.

None of these had automatic line compensation, just a resistor and capacitor circuit.

dsk

[unbeldi]

The Ericsson Dialogue telephone was made under licence in many countries.

The name of the design as published by the company was  DIALOG, not ...QUE

Most countries used identical circuits as yours, and the dial was the same with or without lettering depending on local standards. 

The design was used with a variety of dial types actually.   Some initial use was with a DC push button pad for use in Ericsson's DC signaling exchanges.  The standard rotary dial for the public release was an Ericsson dial that had been used by the company since the late 1940s.

The dial letters indicates Danish.   Sweden use 0 at 1 pulse.

IIRC, the original publications show the standard 1...9 0 sequence.   The found set probably only has a Danish number ring.

None of these had automatic line compensation, just a resistor and capacitor circuit.

This is incorrect for general consumption. Perhaps some administrations replaced the network with simple circuits, but the Dialog was designed with a self-compensating network using varistors.  The design criteria and performance characteristics are published in detail in the same reference (same issue) I already quoted.  The designers were well aware of the work in other administrations, especially the work at Bell Labs and they quote their papers (Bennet, "An improved circuit .... ", etc).   The design also was based on CCITT recommendations for transmission characteristics.  Ericsson also performed similar ergonometric studies as conducted by Bell to optimize transducer performance mechanically.
Construction was from ABS plastics in many colors.
Overall, the design had a similar technical sophistication as the Type 500 set in the US.   

[dsk]

Great info, all I have seen has only had resistor/capacitor in the sidetone balance circuit  (zb) and no varistors.

dsk

[dsk]

The thread about mine:  http://tinyurl.com/y7v5b5s8   Pretty equal to the railroad phone:

[unbeldi]

The thread about mine:  http://tinyurl.com/y7v5b5s8   Pretty equal to the railroad phone:

That is not an Ericsson Dialog. [No, but it is an EB Oslo Dialog, see later posts.]  It is the old Norwegian circuit that was used since the 1950s or longer, and put into several housings, last into a copy of the Swedish Dialog housing, sometime before 1967.   In 1967 the PTT radically changed the electronics of the set to using a dynamic microphone, the same element as used for the receiver, and placed a transistor amplifier on the board without a ringer. Instead of the ringer it used a 2500 Hz tone emitted through the receiver.   This was the Norwegian Model 67, still not a Dialog, but looked like one.

A more interesting question is what is actually inside this Danish version and who actually built the set.

[Alex G. Bell]

That is not an Ericsson Dialog.   It is the old Norwegian circuit that was used since the 1950s or longer, and put into several housings, last into a copy of the Swedish Dialog housing, sometime before 1967.   In 1967 the PTT radically changed the electronics of the set to using a dynamic microphone, the same element as used for the receiver, and placed a transistor amplifier on the board without a ringer. Instead of the ringer it used a 2500 Hz tone emitted through the receiver.   This was the Norwegian Model 67, still not a Dialog, but looked like one.

A more interesting question is what is actually inside this Danish version and who actually built the set.

Interesting and kind of progressive of them to eliminate the carbon transmitter so early.   Seems like it might have inherently had more constant transmit level with respect to loop current than a carbon transmitter too, though not necessarily sidetone nulling.

I wonder how it worked out in practice.  I would not have thought a single transistor (as I think DSK stated previously) would have provided sufficient gain.

[unbeldi]

E. Roth's 1970 technical review "Telephones across the World" states that even the Swedish administration did not use the Ericsson Dialog design circuit, but also used their traditional bridge circuit.

[unbeldi]

Interesting and kind of progressive of them to eliminate the carbon transmitter so early.   Seems like it might have inherently had more constant transmit level with respect to loop current than a carbon transmitter too, though not necessarily sidetone nulling.

I wonder how it worked out in practice.  I would not have thought a single transistor (as I think DSK stated previously) would have provided sufficient gain.

Right.  Here is the circuit, it had two transistors.

Ref:  E. Roth, Fernsprechapparate in der Welt.  p.122