Chapter 5. Calibrated RF Source

We will be building the first of two RF projects in this chapter. In order to calibrate the power meter in the next chapter, we first have to build ourselves a calibrated RF reference. I am going to assume that you know how to make measurements using a spectrum analyzer. If you're building an RF project for the first time, I'm sure a local ham radio club will be happy to help you out. They'll probably want to build one themselves.

What we are going to do is use a factory-programmed crystal oscillator (Digi-Key) and another crystal of the same frequency as a filter. The manufacturer's part number for the oscillator is MXO45HS-3C-50M0000. The other parts are listed in the bill of materials, which is available for download along with the PCB and schematic files.

A crystal is simply a piece of quartz that has been cut and tuned to a specific frequency. A crystal oscillator contains a tuned crystal and other circuitry to generate a...