The project in this chapter was probably more challenging than the previous ones, so I hope you were successful and made some new friends in the local ham-radio community.
We learned about crystal filters and how they work. We also learned about crystal oscillators and how they work. The oscillator we used in this project is a simple crystal oscillator. There are two other types of fixed-frequency oscillators that you might have heard of and can substitute if you like.
The first type is called a TCXO, which stands for Temperature Controlled Xtal Oscillator. This oscillator has a built-in heat sinking ability that keeps the crystal at a fairly constant temperature. A crystal's frequency can change slightly with temperature, so this makes a TCXO more accurate than a simple crystal oscillator, and more expensive.
The second type is called an OCXO, which stands for Oven Controlled Xtal Oscillator. As the name implies, the oscillator package contains a heater that keeps the crystal at a...
