Telegraph Demonstration

A simple telegraph transmitter and receiver can be made using some empty beverage cans and a couple of battery powered tea lights. I made it to demonstrate how distance communication worked in the 2nd half of the 19th century and as a useful way to learn More code.

2 empty aluminum beverage cans

Cardboard

2 Battey powered tea lights.

2 hookup cables

A couple of beverage cans will be used in making this simple telegraph. The paint needs to be removed from the cans so a good electrical connection can be made. There are two simple ways to do this:

1. Rub the paint off a full beverage can using a course scourer.
2. Once the metal from the can has been flattened, remove the paint using 120 grit sandpaper.

Remove the top and bottom from two aluminum beverage cans using a sharp knife. Trim the rims with a pair of scissors. Cut down the length of the of a can and then make flat by moving the aluminum sheet against an edge.

A couple of Morse code keys can be made out of each of the flattened aluminum sheets.

1. Cut each of the sheets in half to form squares with an offset wire connecting tab.
2. Sandpaper the connection tabs to make good electrical connections.

Removing the battery and LED from a small battery powered tea light, makes great signal lights to use with the morse code keys.

Place the small battery on one of the sheets and secure with a little glue. Cut out some cardboard and fit around the parameter with glue. Place the other sheet on top and test the connection when pressed down in the middle to check the LED fitted between the two connection tabs lights up.

Connect the two keys with some wire. I used some leads with crocodile clips on the ends to demonstrate how telegraph works but you can also use wire made from some beverage cans for longer distances.

More code is sent as a series of dots and dashes.

To assist with understanding morse code there are some web sites worth checking out. Some will do the translation for you.

... . -. -.. / -- --- .-. . / -... . . .-.

To Send morse code longer distances, just have longer wires between the two morse code keys. Here's how you can make some wire from empty Beverage cans.