This is a low frequency sine wave oscillator featuring low distortion, wideband operation and crystal control.The circuit, originally developed for laboratory use, employs low cost AF bipolar transistors for the oscillator and amplifier sections and a JFET for loop-gain control.
A simplified schematic of the oscillator circuit used in Chrontel products is shown in Figure. Note that the typical 2-pin crystal has been replaced by its equivalent circuit model.
The circuit below is a standard oscillator of the Colpitts variety. Similar circuits have been used in many ham radio homebrew transmitters.
The majority of clock sources for microcontrollers can be grouped into two types: those based on mechanical resonant devices, such as crystals and ceramic resonators, and those based on electrical phase-shift circuits such as RC (resistor, capacitor) oscillators.
Sometimes there might be a requirement for a non-standard crystal oscillator. While most crystal manufacturers will grind a custom crystal for you, it would obviously be much cheaper and quicker for you to make your own. Bear in mind this project is suitable only for those people who are well acquainted with electronics and soldering.
with the assistance of stabilization and tuning tricks, crystals makes an ideal frequency reference for wireless systems.