Question concerning modular plugs

[Robert63]

So with information that I have gleaned from this valuable forum, I have been renovating a 1954 Western Electric 354. I have nearly completed my work, just waiting for a new handset cord (original cord was completely deteriorated) to arrive in the mail. My question concerns wiring a modern modular plug, which I have done, along with ensuring the correct wiring to the rest of the phone (many thanks to Bill Jeffery's wiring diagram, a great time saver). I know where the green, red, & yellow wire are connected to in the phone, but not the black wire. Most 4 wire modular jacks have a black wire, and my assumption is that the black wire is not used. So am I right?

[WesternElectricBen]

Welcome to the forum!

FORGET ABOUT BLACK! And sometimes yellow, I will usually cut off the black and yellow so they don't cause any problems. Make sure to also correctly store them where they wont interfere in the phones performance. Those colors don't really do anything on a single line telephone. Unless it has a light kit.

We would also love to see your 354.

Hope that helps!
Ben

[G-Man]

In practice, generally it is best to never cut-off wires inside of the instrument but to follow the telephone company practice of store and insulate instead.

In this instance, if at a future date you wanted to connect a single-line instrument to a 1A1 or 1A2 key system or implement some other feature, you would need both of those wires.

[WesternElectricBen]

In practice, generally it is best to never cut-off wires inside of the instrument but to follow the telephone company practice of store and insulate instead.

In this instance, if at a future date you wanted to connect a single-line instrument to a 1A1 or 1A2 key system or implement some other feature, you would need both of those wires.

But, he is adding a moduler plug... I have never seen a moduler 1a1 or 1a2.

[poplar1]

In practice, generally it is best to never cut-off wires inside of the instrument but to follow the telephone company practice of store and insulate instead.

In this instance, if at a future date you wanted to connect a single-line instrument to a 1A1 or 1A2 key system or implement some other feature, you would need both of those wires.

But, he is adding a moduler plug... I have never seen a moduler 1a1 or 1a2.

500MM and 2500MMG are 2 examples of single line phones used with 1A1 or 1A2. You can also convert most single line phones for 1A1/1A2....you would use the yellow and black for your A and A1 leads.

[G-Man]

But, he is adding a moduler plug... I have never seen a moduler 1a1 or 1a2.

Perhaps he will never use his telephone with any other options but good telco practice dictates wires to be stored and insulated instead of being cut-off.

In the collectors world it is wise to do so, especially with a 4-wire modular jack since at some point you may need to replace it with a 3-wire version and reuse it for another project. Some of these parts are/will become scarcer as time goes by.

Here is an example of a 1A2 key system wired with modular jacks for use with single-line instruments:

[WesternElectricBen]

Yes, that is a good point G-Man, I should do that, thanks!

And, uh, G-Man, that's mine.

The reason why their is modular plugs is so you can plug in a cord that connects to the c.o. I use multiline phones on it, not singles..

Ben

[Robert63]

Thanks for all the great information, again this forum is the best source of information of its kind on the internet. I made my own modular plug with just the three wires (yellow, green, red) so storing the black wire is not going to be a issue. Again guys, thanks.

[G-Man]

Yes, I know that it is yours; from your comment I thought that perhaps you did not know that it is a 1A2 system:

But, he is adding a moduler plug... I have never seen a moduler 1a1 or 1a2.

Yes, that is a good point G-Man, I should do that, thanks!

And, uh, G-Man, that's mine.

The reason why their is modular plugs is so you can plug in a cord that connects to the c.o. I use multiline phones on it, not singles..

Ben

[WesternElectricBen]

Yes, I know that it is yours; from your comment I thought that perhaps you did not know that it is a 1A2 system:

But, he is adding a moduler plug... I have never seen a moduler 1a1 or 1a2.

Yes, that is a good point G-Man, I should do that, thanks!

And, uh, G-Man, that's mine.

The reason why their is modular plugs is so you can plug in a cord that connects to the c.o. I use multiline phones on it, not singles..

Ben

I knew that..