So, you have gotten yourself a vintage Dutch telephone and now you want to connect it to your telephone line. Technical information on the internet about this subject is often only understandable for experts. Here is an explanation for normal people. It really is only down to 2 wires.
Please mind that the colors and their meaning are according to the so called Norm 51, technical specifications and requirements for telephones from 1951 and later. They apply to most Dutch telephones, even to the ones from before 1951.
The PTT plug
In the times before RJ11 connectors almost every country had their own 4 pronged plug. In the Netherlands PTT had their socalled PTT plug. It was in use from the 1950s till and you can even buy new ones today.
If you have a telephone with this old style plug, you can of course change it for one that you can use in your own country. Personally I prefer, for originality’s sake, to leave old plugs on.
Adapters for PTT plugs to RJ11 are available on line. You can see an axample of on in the picture on the right. If you have trouble finding one, please contact me.
You can by one from me for 2 euros + shipping costs. With one of these connecting your antique Dutch telephone is like LEGO.
The colors explained
Of the four wires, only 2 are really important. They connect your telephone to your provider. The picture below shows the inside of the PTT plug, showing the different colored wires and to which prong they are connected.
The 2 connecting wires are the A wire (RED) and the B wire (BLUE). These are the positive and negetive.
The symbol with the GREEN wire, the three horizontal stripes with the vertical line, is for the E wire. E stands for Earth, or ground. Some telephones have a white button, a so called earthing button. This wire did have something to do with the functioning of that button. This wire is not really needed and has no function today.
The last wire is the EW (YELLOW). EW stands for Extra Wekker, extra bell or extra ringer. Sometimes EB or W2 is used. This allowed an extra ringer to be connected.
Get the ringer working
You have the telephone connected up and you have dial tone, but it does not ring on an incoming call? To make the ringer in the telephone work, you will need to connect the EW wire (YELLOW) together with the B wire (BLUE).
Often this connection has already been made inside the telephone. Even when that is the case, and if you also connect the yellow wire to the B connection, the ringer will still work normally.