In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be either fixed... [more]
This circuit is deliberately limited in power output but will provide amplitude modulation (AM) of voice over the medium wave band. [more]
This low-cost short-wave transmitter is tunable from 10 to 15 MHz with the help of ½J gang condenser VC1, which determines the carrier frequency of the transmitter in conjunction with inductor L1. The frequency trimming... [more]
circuit from:http://www.extremecircuits.net/2010/05/simple-short-wave-transmitter.html
There are not many AM transmitters that are easier to build than this one because the inductor is not tapped and has a single winding. There is no need to wind the inductor as it... [more]
circuit from:http://www.extremecircuits.net/2010/05/simple-am-transmitter.html
AM FM Simultaneous Transmitter Using Digital IC [more]