In this video, I document the successor to Heathkit's first digital product, their model IB1101 frequency counter (their first digital product was the IB101, which looks identical to this IB1101 but with a lower frequency range).

I cover the history of this model, my restoration of it to fully working condition, I demonstrate it in operation, I describe the circuit theory of operation, and I also tack on to the ending a brief look at how I designed and 3D printed a new light shield for the Nixie tube display.

Not included in this video is the resolution of the presumably failed input signal clamping diodes, which I had partially unsoldered for the entire period documented here. After I uploaded this video, I received the 'new old stock' FD777 diodes ordered on eBay, and installed them. The old diodes were then tested; one was 'open' while the other was shorted. No wonder the counter did not work with those diodes in the circuit......

My newly CAD drawn IB1101 schematic, calibration, etc; document, and also my 3D printable "light shield" STL file, may be downloaded here: www.serpentwebsite.com/fileshare.htm

Timeline Table of Contents:
00:00 Introduction & history
04:54 Restoration
18:38 Internal tour
30:55 Heathkit manual
45:36 Frequency range issues
47:37 Final assembly
48:22 Demonstration
54:48 Beauty shot
55:36 Schematic diagram/circuit theory
2:04:27 Designing & fabricating a light shield