This low-cost AM transmitter is tunable from 10 to 15 MHz with the help of ½J gang condenser VC1, which determines the carrier frequency of the amplitude modulation transmitter ... RFC1 is used to ...

The answer is, of course, obvious: build your own AM transmitter, too. AM modulation isn’t that hard ... Maybe something like “What kind of materials block radio waves?” ...

The more unique conditions that can reliably travel from a transmitter to a receiver ... but quadrature modulation is normally implemented in a system with a block diagram shown in Figure 2. Figure 2 ...