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How to Build a Practice Keyer for Morse Code

You can build a practice key, used to learn Morse code, from just a few household items and one or two components found at an electrical retailer. Samuel Morse developed the invention of the telegraph, which had been previously demonstrated by Joseph Henry in 1830. Alfred Vail designed Morse's first telegraph key in 1841. Morse code is made up of a series of dots and dashes, which, in different combinations, represent letters of the alphabet. Little prior electronics knowledge is needed to build a fully functioning practice key.

Things You'll Need

9-volt battery
Electrical tape
Wood blocks
22-gauge wire
Side cutters
9-volt electronic buzzer
Aluminum sheet
Thumb tacks
Bendable metal
Screw

Instructions

- 1
  Mount a 9-volt battery to a small, wooden block using electrical tape. The block needs to be approximately 5 inches square and one-half-inch deep. Looking from above, mount the battery on the left side with the terminals facing the top.
- 2
  Cut four lengths of 22-gauge electrical wire to 6 inches with side cutters. Strip back an inch of the insulation from both ends of each of the wires. Wrap one exposed end of two of the wires around each of the battery's terminals. Use electrical tape to fix the connections in place.
- 3
  Mount a 9-vVolt electronic buzzer to the middle of the block of wood with electrical tape. Connect one of the two wires running from the battery to one of the buzzer's terminals. Some buzzer's will have a wire tail to connect to, others will have a screw terminal. Take one of the two remaining 6-inch lengths of wire and connect it to the buzzer's other terminal.
- 4
  Test the buzzer sounds by bringing the two exposed sections of both unconnected wires together. Disconnect them and loop both the exposed sections around on themselves to form small hook shapes. Wrap each hook around the pin of a thumb tack. Use side cutters to cut two small rectangles of aluminum sheet. They should be about .5-by-1 inch. Mount each of them onto the right of the wooden block by pushing each of the thumb tacks through the middle of each rectangle. Keep the wires connected to the thumb tacks by their hooks. Mount each rectangle on the right side of the block about 3 inches apart to form two terminals. At this point the circuit should be open.
- 5
  Cut a 4-by-.5-inch rectangle of bendable metal to form a key switch. Bend it so that 1 inch can sit flat on the wood block with 3 inches sticking up at an angle. Screw the smaller area into the wood block through one of the two aluminum terminals you have made. Ensure they make a good connection. Position the metal so it will reach the other terminal if pushed down. Wrap some electrical tape around the middle of your key switch so you can push it without having to touch the metal.
- 6
  Push the key switch down so that the unscrewed end forms a connection with the other aluminum terminal. This should close the circuit and cause the buzzer to sound. Adjust the key switch so that only a light touch is needed to close the circuit and ensure that when pressure is released the circuit opens again.

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