Basic RF Oscillator Circuit Diagram

This basic circuit is simple to create and the tool's are not critical . Most of them can be found in your junk parts box .

The L1 antenna coil can be made by close winding 8 to 10 turns of 22 gauge insulated hookup wire around a 1/4 inch form such as a pencil .

You can exeprement with the size of the copile and the number of  turns to see how it affects the frequency and singnal out put of the oscilatter .

You ought be able to pick up its signal with a standard FM radio receiver . The signal in ought be coupled by a disc capacitor of about 0.1 uF to stage in main of it .

Author 

          Saifullah soomro

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VFO circuit Diagram with Varicap Circuit Diagram

This is the simple project of VFO circuit Diagram with Varicap Circuit Diagram. The most difficult to build an oscillator VFO (in Portuguese OFV variable frequency oscillator) is to get him to have a good frequency stability, for it must feed the VFO with a source of good quality, make the short connections and shielding in a box metal. 

This circuit operates up to 10 MHz frequency and can be used for testing since it is quite simple. In this project VFO is used 1N4001 rectifier diode common that can work as a varicap when polarized in reverse. The coil L1 is formed by 80 turns of 28 AWG wire on a ferrite rod 1 centimeter in diameter. For the RF transistor may be a transistor used BF494.

 VFO circuit Diagram with Varicap

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