Heathkit IM-12 Harmonic Distortion Meter: History, Restoration, Demonstration, Theory

In this video, I describe the Heathkit IM-12 Harmonic Distortion Meter. I talk about its history, restoration, and making a new 3D printed lamp socket holder for it. I then briefly demonstrate it, show the manual, and give a walk-through of the schematic diagram while describing the circuit theory of operation. Timeline Table of Contents 00:00 Introduction & History 05:54 Overview (internal & external) 19:16 Restoration 31:29 New 3D printed lamp socket holder 47:45 Test & Demonstration 1:00:15 Beauty shot 1:00:33 Overview of Heathkit's manual 1:10:29 Schematic & circuit theory