HP 5212A Electronic Counter
Kirt's Cogitations™ #302

This rare HP 5212A Electronic Counter was found in a second-hand shop sitting in with a bunch of random electronic gear. The "HP" on the front panel piqued my attention, so I carried it to the sales desk and asked the nice lady to plug it in, figuring if the front panel lit up and none of the smoke that makes electronics work leaked out, I'd buy it. It did, it didn't, and I did, respectively. The outside condition is pretty good, with most of the scratches being on the top and bottom. Some oxidation is present on the bare aluminum chassis components, but a little rubbing with a Scotch−Brite pad and some clear lacquer would take care of that. You can order matching paint from numerous suppliers if you want to completely restore the top and bottom covers. The front panel is in very nice condition and really does not need rework. It could easily be restored to museum quality.

If you are a vintage test equipment collector, you are welcome to purchase this HP5212A for a mere $350, and that includes packing and shipping to anywhere in the lower 48 states.

The HP 5212A Electronic Counter uses all solid state circuitry - probably one of the first such products from Hewlett-Packard. Its vintage is sometime in the mid 1960's. According to documentation* found on the HPArchive.com website, the maximum calibrated operational frequency is 300 kHz, although my tests show it works up to 550 kHz with sine, square, and triangle waveforms. Both frequency and period can be measured, and there is a cycle counter as well, all of which appear to function properly. The internal reference oscillator was used in my tests, but there is a jack and switch on the rear panel for using an external reference if available. A parallel port plotter / recorder connector is provided on the rear panel, but I did not test it.

* Click here for excerpt I created of just the HP 5212A Electronic Counter portion of the document.

I removed the top, bottom , and side covers and carefully removed all the plug-in printed circuit boards for cleaning. The covers, frame, and front and rear panels were cleaned with Windex. A vacuum cleaner and compressed air got rid of most of the accumulated internal dust (of which there was amazingly very little). CRC QD Electronic Cleaner was sprayed on all the PCB edge contacts and the chassis connectors, and then the PCBs were re-installed. CRC cleaner was also used on the switch contacts and on the external connectors. A careful "sniff test" did not reveal any suspected overheated components. Both fuses were in good condition.

At first I started taking a bunch of photos with a signal generator sitting on top of the HP 5212A Electronic Counter to show good agreement between the modern instrument and the vintage instrument, but then decided that a short video would do a better job.