Here is an extremely easy device to make (an invention of my own) By TonyPro
You will need:
2 Paper clips (or very thick uninsulated wire)
1 nail
About 8 inches (or thereabouts) of extremely thin, insulated wire (medium gauge magnet wire is perfect)
1 square piece of flat styrofoamStyrofoam (or anything you can stick things in, really)
1 square inch of tape
1 square inch of tinfoil (or any small metal object)
1 battery (use a 9 volt at least)
Several miles of wire (I am not joking; see below text for an alternative)

I believe the diagram below is fairly legible (I flatter myself). Important things:
-The wire wrapped around the nail should be in a tight coil--you shouldn't be able to see any of the nail apart from the top and bottom.
-Press down on the paper clip so that it touches the tinfoil square. stick it to the ring of tape so it springs back up when you release it.
-There needs to be space between the unbent paper clip and the nail head. The point of this thing is that when someone presses down on the paper clip it closes the circuit, turns the nail into an electromagnet and makes the paper clip come down to 'tap' it, allowing one to 'tap' out a message.
Get the person you wish to communicate with to make the other one, and connect them with wire as directed. The biggest disadvantage to this, of course, is that it requires enormous lengths of wire. If the nearest settlement to you is, say, five miles away, having made this device, one would have to obtain ten miles of wire, and get a volunteer to run to the other base, fending of Z's and laying down wire all the way. This is ridiculous. Here is a sneaky trick--use the phone lines. Of course, the phone network will be down; but if the phone lines are still up, simply scamper up a pole, tear down a wire (for this you'll want to be SURE that the lines have no power!) hook it up to your Morse code device (you'll need to attach every tiny wire), and get the people at the other base to do the same with theirs. It would be much easier to strip the wires from a phone cord, plug it into your wall, and attach that to your device; but it is very possible that it won't work that way. The only thing you must be sure of is that there are no transformers (those big roadside metal towers and columns the phone lines run through) between you and your contact. Regardless this contraption is terrifically easy to make with the limited materials one would have at one's disposal, and runs off of any kind of battery.




Another Idea I Just Had For A Wireless Morse Code Transmitter

This would work for a very short range transmitter; but it's wireless, and even portable.

-Take apart a remote control car
-Using wires, replace the little batteries in the remote controller with those big square 6 volt flashlight batteries--use at least three, connected in a loop.
-Remove the motor from the car components and hook the wires that were connected to it to an electric buzzer or a speaker from a pair of headphones or from a small radio (the speaker won't make any noise; just a little click, which is just what we want)
-When the 'drive' control on the remote controller is pressed, the car's system, which normally would activate the motor to turn the wheels, should activate the noisemaker (if you've used a buzzer, make sure the polarity is correct).

Note: You should use a good quality, powerful RC car for this. This will not work with a Zip-Zap. Even so, this will have a range of no more than half a mile. The more voltage you use, the more range you'll have--that is, unless you use too many batteries and short circuit it; frying the car and burning your fingers. Hey, this isn't exactly super-advanced technology.