I need to make a cheap radio wave generator. Can any one tell me how?

Question

I need to make a cheap radio wave generator. Can any one tell me how?

Answer 1

Can't answer this without knowing what you need to do with it.  The answer would depend on the application.

Answer 2

What sort of radio waves? what frequencys, what power level? for what purpose?

Do you want to transmit information?,  for example sound, of remote control signals, if so, what sort of receiver will you be using? you will want "radio wave generator" to mach the receiver.

a simple spark gap will generate wide spectrum radio frequency noise, and be cheap, but it might not be very useful for most uses, though the first radios did use spark gaps, and the high frequency generator in my (some what out of date) TIG welder uses a spark gap

Answer 3

With a power supply and a LRC circuit (inductor, resistor, capacitor) you can make a cheap radio wave generator.  This is how radio waves were originally broadcast.