This is a simple but functional key and code practice oscillator (sounder or sidetone generator) for learning Morse Code made from a steak-knife and multi-tester. This project includes making the key and using a multi-tester as the sounder. An additional benefit of the multi-tester is that it also flashes an LED so you can see your Morse Code too. Few components and only takes half hour to construct. And when you are finished practicing Morse code you can put the knife back in the kitchen drawer.
block of wood
2 inch binder clip
4 small magnets
multi-tester or volt-meter that has resistance tester (ohm-meter) with sound
I basically got the idea to use a steak-knife from K4IBZ's Beef Eater Special here: http://oldsite.w4aaz.org/attachments/BEEF_EATER_SP...
There are many homemade keys out there on the web. Even one made from just paper clips.
Here are a bunch of very innovative homemade keys: https://uk.pinterest.com/sverreholm/homemade-singl...
Step 1: Make Key
Cut block of wood to size you want for keyer base. A little bigger is better as it needs weight to keep from sliding around when you use it.
Cut two smaller pieces, one about the size of a 2 inch binder clip. cut the second about the same size and drill a hole in one side for a screw that serves as a contact.
I drilled a hole part way through the bottom of both small pieces and inserted small dowel. Glue them to the base board.
And that is all the cutting and drilling to be done.
Step 2: Put It All Together
Insert clip binder over wood block. Insert knife into binder.
Adjust screw contact by turning it in or out until it doesn't quite touch the knife blade. You can probably get a little better contact and therefore sound with less chirp by slightly flattening the tip of the screw with a file.
Attach magnets to each probe of a multi-tester and adhere one probe to the knife and the other to the screw.
I put some dabs of hot glue on the bottom of the base to keep if from sliding around on the table. You may still have to hold it with one hand to keep it from sliding unless your base is very heavy.
Turn on multi-tester to ohm-meter sound setting.
The knife provides a nice solid yet easy to press lever.
And you are done. Have fun learning Morse Code.
73 de Jim, KE8BSH