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You can build a simple morse code transmitter that can be received by a regular AM or FM radio. I seem to remember seeing schematics for these in some of the Forrest Mims books.
It would be helpful to know how far you want to transmit and if you care what kind of parts are in the circuit (tubes, transistors, ICs, etc.). Do you intend to build the receiver or use an off-the-shelf radio?
By the way, you should consider posting this on eham.net in the "homebrew" category.
That picture is an intersting application of the simplest broadcast transmitter called Galena. Requires few amount of electronic components. Repair that no intermediate frequency is used.
However this kind of transmitter takes a wide band of RF spectrum and may be considered just for emergency purposes. At normal operation you should work under hiperheterodine topology circuit.
If you intend operate this equipment need perform a survey at your country regulations regarding what are the free use radio frequency spectrum ranges.
Answering your question : The receiver you can build also simply like bellow :
Oh no! I'm just glad North Dakota is a long way from here.
@Fworg64 this is exactly waht Marconi used in the very first 'wireless' broadcast. Spark transmitters are VERY broad band, you don't tune into them as such because they produce a signal which covers the whole band and these days would be regarded as interference. They also don't produce Morse Code in the accepted sense, you will not hear dots and dashes or even a tone, just a clicking noise. You would do far better to look at simple keyed oscillators which you can pick up on a domestic radio. Even a simple single transistor oscillator will have tens, maybe hundreds of times the range and it will produce a continuous signal when the key is held down rather than a single click as it is released.
The original post is for a radio transmitter, you show an audio oscillator. It may well radiate interference if an antenna is attached but only due to harmnics of the NE555 output.
What is being suggested is a keyed RF oscillator that can be tuned on a normal AM radio.