Make: Radio

55Experiment 3: A Real AM Transmitter

ADDING AUDIO

The next step is to add an audio input and a

tuning capacitor, as shown in Figures

3-4

and

3-5

. The tuning capacitor is the same type that

you used before, and we are adding it so that

you can adjust your transmitting frequency just

in case there happens to be a radio station near

where you live whose frequency you want to

avoid.

The component at the left end of the

breadboard is an adapter in which an audio

jack is connected with three screw terminals.

Most adapters have their terminals labeled

with L (left channel), R (right channel), and the

ground symbol. A few adapters have screws

labeled ...