There’s a transformer for the linear supply, through-hole components, and an Intersil frequency counter on a chip. Everything is easy to get to and large enough to see.

But there were other looks for test gear back in the day, as this frequency counter with a readout using moving-coil meters shows. We have to admit to never seeing anything like [Charles Ouweland ...

LED Display, 3.5 GHz Operating Frequency, External Frequency Standard Input, Frequency Counters. The model 1856D provides versatality and reliability for a broad ...

Image Credit: Allied Electronics, Inc. Frequency counters are digital devices for accurate measurement and display of square wave and pulse input signal frequencies. A frequency counter is an ...