We covered a great deal of content in this chapter. We built and tested a frontend for a software oscilloscope and an audio signal generator. We also looked at several useful software packages available for free in some cases. We also saw some additional hardware that allows us to use the sound card to measure impedance, inductance, resistance, and capacitance. In addition we also learned how to build an active rectifier / envelope detector.
You will find the ZRLC and envelope detector printed circuits on the same panel for manufacturing. That way, if you order your boards from EasyPCB, you will get three of each. In the next chapter, we will be venturing into the mystical world of RF design. In spite of what some HAMs may tell you, there is nothing magical happening here (at least at these frequencies)—just a few simple rules that, if followed, will lead to success.
