A Talk About Impedance Bridges: General Radio 650 and Heathkit IB-1

In this video, I talk introduce the subject of impedance bridges, and present a brief primer on the subject. Then I show and talk about the 1933 General Radio 650 impedance bridge. Next, I discuss the history of Heathkit impedance bridges, and demonstrate the Heathkit IB-1 (and IB-1A and IB-1B) impedance bridges dating from 1949. Finally, I describe a few hacks useful to impedance bridges like these.