Exercise 2L.1.1 calls for figuring out the RC constant, and then R and C of an RC low-pass filter. In their lab, the authors hand the students a “wrapped” R and C pair. Since I didn’t have that option, I had to improvise. I had a pair of Elenco Resistor and Capacitor Substitution Boxes. I pulled off the knobs, spun them in my hands, and then reinstalled them and spun the boxes to random settings. Instant mystery filter. (Of course I then had to use a DMM and an LCR meter to reinstall the knobs correctly…)
Despite the book’s careful explanation, I initially set the oscilloscope time base too short, and struggled to get correct values. Eventually, I figured it out….
Exercises 2L.2.3 and 2L.2.4 gave me real pause and stopped me for quite a while. They called for using a transformer to examine noise on the 115V electric mains. While the transformer was one of the items on the parts list, it came as a bare transformer with some wires. I wasn’t about to stick the bare leads into the socket. Just soldering on an extension cord also seemed unsafe. So a more elaborate safety enclosure seemed in order. Details in Part 2.