The carrier is amplified by transistor T4 and coupled to RF amplifier transistor T1 BD677 through transformer X1. The AM radio transmitter does not use any modulator transformer. The audio output from ...

A crystal radio is a common enough science fair project, but the problem is, there isn’t much on anymore. The answer is, of course, obvious: build your own AM transmitter, too. AM modulation isn ...

AM radios are relatively simple devices, and building one is a good way to start exploring the world of radio communications ... testing two popular 555 transmitter circuits.