Two Way Radio Technology
History | Uses | Types | Two Way Radio Frequencies | Push To Talk | Make Your Own

Make Your Own Walkie Talkie

We all have old phones. Why not turn them into an intercom or turn two old cordless phones into home base walkie talkie?

Materials:
In-Line coupler
9 volt connector
wire-nippers
Dremel
Soldering iron
solder
300 ohm resistor or close to it
black electrical tape
two telephones
two telephone cords

Step 1: Open your coupler
Apply pressure to break it open at the center. You will see 4 wires, they should be color coded red, green, yellow and black. If they are not, it will be harder. The red and green cables are the one you should worry about. The other two are for the second line; it will not affect this project at all.

In Line Coupler

Step 2: Cut, strip and solder
Cut the red wire in the middle. You now have two red wires. Strip the ends of both red wires. Now you will need some basic soldering skills for the rest of this project.

Now solder one side of the resistor to one end of the red wire. Solder the other end of the resistor to one end of the 9 volt connector (it doesn't matter witch end). And the last side of the 9 volt connector will connect to the other red wire. It should look something like this. Now when you do this cut off exess wires from your resistor and 9 volt connector before you solder, remember it all has to fit back into the coupler when your done.

Step 3: Testing
Quick test, leave it open Plug two phones into both ends of the coupler put in the 9 volt battery and talk. You may use two old wall phones with no problems. If you use cordless you need to make sure you have power going to them before they will work.

If they work seal the expose wire with black tape. Dremel out a little slit into one of the sides. This will be where the 9 volt connector wires will exit the coupler. Close up the coupler, and be careful not to break any of the soldering you did earlier. Bring the leads of the 9 volt connector out of that slit.

Step 4: Clean Up


What is the purpose of the 9V battery?

Originally it powered the phone. In the olden days phones didn't have power cords you just plugged them into the wall. The phone line would not just carry the signal but also power the phone. Because local electric power and phone power were two separate sources that is why some phones will continue to work with the power out. But modern cordless phones have lost that function. To be more specific the 9 volts is used as a carrier. And voice is sent as fluctuations in this 9 volt potential.

Find more cool projects at Instructables.com.