Ericsson DBK1001T

[LarryInMichigan]

I just picked up this phone from a local ebay seller and am trying to find information about it.  The bottom is marked "DBK1001T" and there is an illegible decal.  The phone is quite small, measuring about 6" x 4.75" at the bottom.  I tried connecting the end of the line cord to my phone line, but I got no dial tone.

Is this phone capable of working on a standard phone line?  Where can I find a wiring diagram?  There us a terminal block, but the terminals are marked with numbers only.

Thank You


Larry

[unbeldi]

Ericsson used an alphanumeric classification system for equipment.

DB are telephone sets (D) made from Bakelite (B).   The third letter was for the manufacturing  location or country, and I think K is Finland.
So, I believe this is the same set that was designated as DBH-1001 in Sweden, which was the first all Bakelite telephone made in 1931.

I think I have a diagram for the DBH-1001 somewhere... will try to find it.

This set is usually quoted as the inspiration for the Western Electric 302.

Really nice find.

[unbeldi]

Well, I still don't have a circuit diagram, but I found the article of the nomenclature system they used.
I was wrong about the third letter.  K stands for a small version of the case. I think, possibly only containing a buzzer rather than a larger ringer.

Here is the ER article about the designation system.

[LarryInMichigan]

Thank you for the information.  I found the DBH1001 diagram on the TCI website (link), and I was able to connect the phone so that it worked.  The sound quality from the transmitter is awful.  It sounds like a 1920s candlestick type.  My problem before was that the test line cord I was using is bad. 

The phone, as I mentioned, is REALLY small, so the 'K' for small case makes sense.  The phone looks rather like a toy.  It has one of those Ericsson gong-less ringer gadgets which makes loud clicking sounds in lieu of ringing.  I am guessing that the "44-41" printed inside means that the phone was made on the 44th day of 1941.  Here is the ebay link for the phone: ebay link.  The seller told me that his father collected phones and that this came from his collection.  I met him today locally to get it.  Unfortunately, a very large chunk of something flew into my car at 70MPH on the freeway on the way, so there is about another $1500 of car repair costs involved with this acquisition.

Larry

[unbeldi]

Thank you for the information.  I found the DBH1001 diagram on the TCI website (link), and I was able to connect the phone so that it worked.  The sound quality from the transmitter is awful.  It sounds like a 1920s candlestick type.  My problem before was that the test line cord I was using is bad. 

The phone, as I mentioned, is REALLY small, so the 'K' for small case makes sense.  The phone looks rather like a toy.  It has one of those Ericsson gong-less ringer gadgets which makes loud clicking sounds in lieu of ringing.  I am guessing that the "44-41" printed inside means that the phone was made on the 44th day of 1941.  Here is the ebay link for the phone: ebay link.  The seller told me that his father collected phones and that this came from his collection.  I met him today locally to get it.  Unfortunately, a very large chunk of something flew into my car at 70MPH on the freeway on the way, so there is about another $1500 of car repair costs involved with this acquisition.

Larry

Shouldn't go 70 on the Jeffries !   

or 41st day of 1944? They didn't get bombed out in Sweden.   Looking at the components they do look more like 1940s than 1930s.

[LarryInMichigan]

It was I-96 in Livonia.  That freeway was completely rebuilt about a year ago.

Sweden was officially neutral during the war, though they allowed the Germans free passage through their territory.


Larry

[dsk]

Norwegian EB catalogue 1938.

[unbeldi]

Norwegian EB catalogue 1938.

1101  =?  1001

[dsk]

The closest I came, This was made in Norway, Larry's seems to be Swedish.  My guess will be a diagram close to this:

Yellow= Ring Black=Tip  Red= ringer (connects together with Black)
dsk

[unbeldi]

I haven't found it in any of the Ericsson catalogs that I have, but I have a list of Ericsson catalog numbers with cross reference to circuit numbers:

DBH 1001     209422 209446 209434 128075
DBK 1001     209423 209447 209435
DBK 1101     209427 209451 209439 230342

This matches the circuit number for the DBH 1001 that is on the TCI site.

[unbeldi]

I also have not found it in my full text search index of the entire old Ericsson Review.

[dsk]

  I see no difference, but if it has a buzzer, it will probably be like a ringer and 1 microfarad capacitor, Load about 2-3 REN

dsk

[Matilo Telephones]

Very nice find. These are quite rare.

Here are my 2 cents:

I know this particular Phone as a knarretje (in Dutch, but the Swedish word knar seems to mean buzzer). It is a smaller version of the model 31.

It was meant to be an extention Phone, like for bedrooms, or as a normal unit for office environments where loud bells were not wanted.

It comes with a buzzer or without one.

The designation 1001 seems to be for a dialless version, so maybe this one was converted?

44 41 as an Ericsson date code would mean year and week number. (possible the other way around).

The is a page in the Swedish database here:

http://www.stsf.org/Schema/DBK/DBK1001.jpg with schematics.

It is also in the 1934 catologue om the Ericsson History website.

Both are pictured below.

[dsk]

Notice the slightly different anti sidetone circuit. The last one has a later LME solution. If it has a buzzer, it should have 2 capacitors.

If the telephone is made after this diagram, a defect capacitor will make it silent. Just short out to test.

The telephone pictured has a 3 wire cord, that looks more like the first diagrams.

Try to connect black and yellow to the line.

dsk

[LarryInMichigan]

Thank you for the information.  My phone is quite a bit smaller than the ones shown in the Ericsson catalog.  It is about 153mm long by 121mm wide.  The height in the back is about 99mm.

The phones works when the line is connected to terminals 1 and 3, and the buzzer works when the line is connected to 1 and 5.

The phone is in pretty good condition, but there are several chips in the bakelite along the edges.

I was guessing that the "M4141" on the condenser indicated a 1941 manufacture date.

The edge of the dial is stamped: "TELEFON A.-B. L.M. ERICSSON * STOCKHOLM 02 41".  Again, I would guess that the "41" indicates a 1941 date.


Larry