Simple AM Transmitter

      Nice to have oscilloscope to check connections on this breadboard mounted project. First, I bent some pins backwards on the Crystal oscillator and thought they were inserted into breadboard.  Bending pins back can look like they are going down into breadboard.    Next,  you turn transformer coil to many windings side if audio signal can power an eight ohm speaker or turn transformer around to fewer winding side if using cell phone audio out signal. Note: 1.8:57.6 at transformer in simulator is coil ohm readings and not number of windings.        The clock oscillator is 1 megahertz square wave instead of sine wave.  I could make out my weak transmitter signal from smartphone 3.5 mm.output (volume all the way up on smartphone)to 1 ohm side of audio transformer. Right side of audio transformer is crystal generated square wave 1 megahertz square wave clock signal. Upper right is modulated AM output from Crystal oscillator at using short wire for antenna. Of course, have AM radio tuned to 1,000,000 Hertz. I used good clock radio with volume all the way up to hear audio I sent to AM transmitter. Information and parts for this kit: https://www.scitoys.com/index.php/transmitter.html      

published 7 years ago