Hi every one most of you guys asked me about some circuit diagrams which are related to transmitters So today I'm going to give you a very simple but powerful circuit diagram.This circuit can transmit signals up to 1Km in an open space.This circuit powered with 12v power supply.Here we have used very popular  transistor 2n2218.When you design this circuit diagram try to fix all the parts in a small area then you can get positive results.Without fixing an antenna don't give the power to the circuit.As an antenna  fix 30cm wire.So enjoy this wonderful circuit