Hello everyone I have faced very strange thing that calpp oscillator (Colpitts oscillator) have different frequency from formulas and big different !
I have used 100uH inductor which I measured its value 100% with inductance meter (and I bought it not made it)
Any way the idea is I always got a frequency about 2.6 MHz and smaller depending on capacitors values , with tow 39pF capacitors and 100uH inductor I must get around 3.6 MHz but I get 2.6 MHz with any capacitors values even with 2pF in other words I have removed the tow capacitors from the oscillator and the circuit still oscillating with 2.6 MHz !!!!!!!!
I can get higher frequency with different inductor only !
You can see real pictures circuit with oscilloscope and the simulated on multisim witch its results is very close to theoretical formulas.
I have used 100uH inductor which I measured its value 100% with inductance meter (and I bought it not made it)
Any way the idea is I always got a frequency about 2.6 MHz and smaller depending on capacitors values , with tow 39pF capacitors and 100uH inductor I must get around 3.6 MHz but I get 2.6 MHz with any capacitors values even with 2pF in other words I have removed the tow capacitors from the oscillator and the circuit still oscillating with 2.6 MHz !!!!!!!!
I can get higher frequency with different inductor only !
You can see real pictures circuit with oscilloscope and the simulated on multisim witch its results is very close to theoretical formulas.
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