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Virtual Museum of Vintage Electronic Counters

This is a unique collection of 1950s test instruments of the type known as electronic counters, or frequency counters. These instruments were the first to count changes in an electric signal using digital principles. They rely on vacuum tubes, though, and digital circuits require many tubes and many related components. This makes the instruments large and complex. But it also makes them interesting, because they are vivid examples of that early period in the history of digital electronics.

There are 37 models, representing several manufacturers, and depicted with hundreds of high-resolution pictures of their internal parts. Each counter is shown from many different angles, with pictures of various sizes, so you can stop at overall views or examine small details.