I have always been a fanatic about old/vintage/ancient/prehistoric electrical instruments. After our recent QSY (the physical type, not the frequency type), I “inherited” yet another huge collection of semi-vintage Hewlett-Packard test devices. It will be one of my dark winter projects to restore some of these gems to their former functionality, if not their former glory. I have some friends who are FAR more skilled at cosmetic restoration of boat anchors and such than I will ever be.
One of my recent non-HP hamfest acquisitions is this nice Heathkit RLC bridge (Photo A), not necessarily a precision instrument, but very useful, nonetheless. I can never resist adopting anything Heathkit.
Now a large percentage of electrical and electronic instruments incorporate some sort of circuit. The classic has countless varieties and variations, but they all perform the is no exception in this regard. In my June 2022 Analog Adventure column, “Using Vitamin K,” I presented a simple bridge circuit as well as a challenge to solve a bridge that wasn’t really a bridge. Here is a nice note (in part) I got from Rick Peterson, WA6NUT:
