Heathkits

I am certain much of my interest in electrical engineering came from my father, Don. He was always tweaking with the family TV, built our first stereo system, invented the first hands free intercom, converted the hall closet into a subwoofer cabinet, etc. In those days there was a product called a Heathkit. As the name implies, one could purchase kits and assemble them at home. Typically radios, and I believe even a TV at one time, Heathkits were not for the faint of heart; they could be difficult. My father built several. One kit was a lie detector. Why he chose that is anyone's guess. None the less, I was fascinated to watch him assemble it and he explained its operation to me (which would later prove to be a mistake). The kit had a large meter on the front panel that registered all the way to one end of that meter if the person attached to the detector was lying. Unlike a modern lie detector, this one was pretty crude. The victim would hold a metal probe in each hand. A small voltage was passed through the probes and the detector measured the amount of conductivity between the two probes. The basis of this test was that a person under sufficient pressure to not be caught would sweat when telling a lie. More sweat, greater conductivity, more voltage passed through the two probes, the meter swung into the red zone labeled "lying". The degree to which it swung equated to the boldness of the lie. Or at least that was the general notion. Once finished my father was dying to try it out. With three children in the family, the oldest of which was a known miscreant (me), he probably didn't have to wait too long for an opportunity to try it out. It would soon come. Tomorrow the crime.