COLPITTS 1 To 20 MHz Crystal Oscillator

COLPITTS 1 To 20 MHz Crystal Oscillator

Colpitts 1MHz To 20 MHz Crystal Oscillator Circuit

This is a simple Colpitts crystal oscillator for 1 to 20 MHz,

Colpitts 1MHz To 20 MHz Crystal Oscillator Circuit

R1 220kΩ
R2 1kΩ
C1 82pF
C2 0.001µF
C3 100pF
C4 0.01µF
C5 0.001µF
Q1 2N3904
XTAL1 CRYSTAL (1 to 20 MHz)

This can be easily made from junk-box parts (provided that a crystal is handy).

2N3904 NPN Transistor General Purpose Amplifier

2N3904 NPN Transistor Pin Configuration

Please send your ideas, which are very important for our success…


Ravindra, Hi...

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10 comments on “COLPITTS 1 To 20 MHz Crystal Oscillator
  1. Mario says:

    I found it better to remove C2, and make C1=1nF, C3=10nF, and C5=100pF, all other being the same.

  2. dani r safii says:

    why’d we use that value of capacitors? do you have any calculation or something?

  3. Dreamer says:

    Is it important to use 2N3904 transistor?
    I’ve build this circuit with BC547 and looks like it works OK, but I don’t know if it could be better.

    Thank you

  4. Manjit says:

    Dlp projector bypass 5pin

  5. Parth Sane says:

    Can the frequency be doubled? I understand this is for the natural frequency. I want to use the second harmonic of 3.579MHz crystal to build a 7MHz frequency source to test my other circuit. Any ideas on how to do that?

  6. Baruch Atta says:

    @almat – just substitute a parallel coil and cap for the crystal and you will have a variable frequency oscillator.

  7. almat says:

    This schematic is not universal for broad frequency range because it`s purpose is for the natural frequency of the crystal.It can be pulled down only with frequency dividers and also needs precise calculation for different crystals.

  8. weelium says:

    i m having some problem in producing a 1mhz oscillator, if i use the circuit that provided here, can i manage to make it?.. and, i have no idea about it, and in an absolutely troubled situation.. thank you..

  9. Advantage says:

    So could I plug the 50mV output of this into an op amp and amplify it? What may be a good amplifier to do that with?

  10. Copied your osc. circuit. Colpitts. I intend to use it in a receiver 455 Khz BFO and hopefully make the crystal series capacitor variable to “pull” the frequency through part of the audio range. Should be more stable than the standard L-C layout.

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