How to make a home telephone system

Using the principles of sound transmission and amplification, we can create a system to keep us in communication over small distances, i.e. we can create a small private line of communication in different areas of our house and even with neighbouring houses. Today, we will look at how to make a home telephone system.

Home telephone exchange



- A radio/recorder with microphone input and headphone output.

- 4 x 8W speakers.

- Duplex cable No. 22 or similar.

- 2 banana plugs that fit into the inputs of the radio recorder.

- 2 wooden, metal or plastic boxes about 30 cm high, 10 cm wide and 5 cm deep.

Assembling the home phone system

First, we are going to create some sound amplifiers. To do this, we drill a couple of holes in each box to fit the speakers. To fix them, we use silicone or another adhesive material of our choice.

Sound amplifiers

Once the sound amplifiersIf you want to connect a duplex cable connection to each speaker of each of the sound amplifiers, it is time to make a duplex cable connection to each speaker of each of the sound amplifiers. The dimensions of each cable connection should be about 5 cm or more, depending on the dimensions of the sound amplifier enclosures.

Cable connection

When making the connection, the polarity of the wires must be taken into account: the red or white line goes to the positive pole, while the other line (usually blue or black) goes to the negative pole. The free ends of the wires are pulled out through a small hole in the back of the boxes.

Now, we make the first connection. The speakers on the underside of each of the sound amplifiers will be connected to the banana type device respecting the polarity (remember that the positive pole is the central terminal of the connector). This connector will be the one that will be connected to the microphone input of the radio/recorder (telephone exchange).

Connection to a home telephone exchange

Repeat the same procedure with the upper drivers of the sound amplifiers and connect them to the headphone input of the radio/recorder.

Then we adjust the volume of the radio/recorder (telephone exchange) and we can speak through the lower speaker of the sound amplifiers and listen through the upper speaker, just like a home telephone.

If we want to increase the number of telephones, we must add as many sound amplifiers as we want, in this way, we can have a home phone system for private communications.

0 thoughts on “Cómo hacer un sistema telefónico casero”

  1. javier perez, it's clear that you went there to steal pencils, you didn't study a single thing.

  2. ....I would like to know if the handset can be wireless.... also, as a hobby I would like to get simple electronic diagrams such as: audio amplifiers, circuits with leds or night lights, etc... this blog is for me the best anti-stress and very educational ....

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