I'm trying to better understand how a simple radio can send/receive EM waves.
I have read that alternating current generates electromagnetic waves. So then if we make a DC circuit and flip the battery around once every second we would be making a 1Hz wave? Like this:
If so then why do we need coils? From this page I can see simple radio circuits all employ a coil: https://www.homemade-circuits.com/spy-bug-circuits/
... The procedures take place rapidly generating a frequency across the coil which is transmitted as carrier waves through the connected antenna.
Can't we just alternate the current on the antenna itself and emit waves? Like this picture: https://physics.stackexchange.com/a/286815
What if we use a coil but then not use an antenna, would the coil itself emit waves?
I guess I'm trying to figure out the relation between a coil and the antenna and why we need both.