N415H

My dad bought me two phones :

1. A candlestick phone with a ring box whose magneto is stuck (photo).
2. A ring box without a handset (photo).

I wanted to connect the candlestick handset to the second ring box.

After some research, I discovered that the ring box (N415H) worked with a different kind of handset :

This is not what I expected.

I thought the N415H had a candlestick base. But no. It's a microphone/speaker combo set.

This ring box uses four wires for the handset : black, red, green and yellow (BK, R, GN, Y).

The standard is the same as today : the speaker is between GN and R and the microphone is between BK and Y.

I also found this nice diagram of the ring box internals : (source)

On the other hand, the candlestick's original ring box uses only three wires : One is the common and the other two are for the microphone and speaker. The screws are labeled RD, GR and Y. I assume RD is the common, GR is the speaker and Y is the microphone, but I am not sure.

I assume the previous owner did not connect the wires to the right screws.

In the handset, the microphone was on white and the speaker was on green.

Here you can see that white is on GR (supposed to be speaker) and green is on Y (supposed to be microphone).

For both phones, the hookswitch is in the handset.

I first had to rewire the candlestick handset. The previous owner rewired it with electrical extension cord and some exterior network cable. (I forgot to take a before picture)

I assume the previous owner only used it as decoration and did not mean it to work.

During and after :

I also added some paper to make sure nothing shorts out :

The cable I used to rewire the candlestick has three wires : black, red and white.

In the ring box, I connected BK and R together and used it as the common (black wire).

I connected the red wire (speaker) to GN and the white wire (microphone) to Y.

I also connected a pair of C batteries :

You may have noticed that I disconnected the ringer. This is because I do not yet have a capacitor to put in series with it and I wanted to test the phone by connecting it to our landline.

The phone works great.

Unfortunately, the microphone and speaker are not very loud.

I assumme adding one or two C batteries will make the microphone louder at the other end of the line.

I want to use the phone as an intercom system in the new house we're going to build.

I already have another antique phone :