Notice: no vintage Hewlett Packard test devices was harmed in the making of this excessively challenging Nixie clock. In fact, if anything, the HP 5245L electronic counter came out much better off than it went into the project.
Beautiful hand-wired backplane in the HP 5245 counter.
We mention the fate of this instrument mainly since we’ve seen our fair share of cool-looking-old-thing-gutted-and-filled-with-Arduinos jobs before, as well as while they can be interesting, there’s something deeply disturbing about losing one more bit of our shared electronic heritage. To gut this device, which hails from the early 1960s as well as features a few of the most lovely point-to-point backplane wiring we’ve ever seen, would have been a tragedy, one that [Shahriar] wisely avoided.
After a bit of recapping as well as some power supply troubleshooting, the video below treats us to a tour of the Nixie-based beauty. It’s a wonderful piece, as well as still rather precise besides these decades, although it did requirement a bit of calibration. turning it into a clock non-destructively needed adding a bit bit of gear, though. Internally, [Shahriar] added a divide-by-ten card to enable the counter to utilize an outside 10-MHz reference. Externally, an ERASynth++ programmable signal generator was utilized to send a signal to the counter from 0 Hz to 23,595.9 kHz, ramping up by 100 Hz every second.
The end result is the world’s most challenging 24-hour clock, which honestly wasn’t even the point of the develop at all. It was to show off the glorious insides of the counter, introduce us to some great new RF tools, as well as as always with [Shahriar]’s videos, to inform as well as inform. We’ve always enjoyed his wizardry, from his look into automotive radars to a million-dollar range teardown, as well as this was one more excellent project.