RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling
2 MB. Its primary purpose was to provide me with ready access to commonly needed
formulas and reference material while performing my work as an RF system and circuit
design engineer. The World Wide Web (Internet) was largely an unknown entity at
the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps
while tying up your telephone line, and a nice lady's voice announced "You've Got
Mail" when a new message arrived...
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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.
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
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.
I have finally listed the
HP 5212 Electronic Counter for sale on eBay. Please contact
me if you would like to buy it. An extensive search has turned up zero instances
of this piece anywhere, so it is likely extremely rare, and therefore valuable to
a collector - especially for one in what seems to be excellent working order.
If a picture is worth a thousand words, then there are more than 30,000 words
worth of descriptions on this page. Enjoy.
HP 5212A internal top overview
HP 5212A internal top-front
HP 5212A internal top-rear
HP 5212A display PCB's
HP 5212A PCB's
HP 5212A rear panel components
HP 5212A power supply
HP 5212A test @ 0.5 Hz
HP 5212A test @ 3.4828 kHz
HP 5212A internal top
HP 5212A internal bottom-front
HP 5212A internal bottom-rear
HP 5212A front view (open)
HP 5212A cooling fan
HP 5212A sensitivity PCB's
HP 5212A function selector switch
HP 5212A test @ 56.089 kHz
HP 5212A test @ 55.074 kHz
HP 5212A test @ 550.46 Hz
HP 5212A internal bottom
HP 5212A external bottom w/cover
HP 5212A internal top left
HP 5212A internal top right
HP 5212A left side
HP 5212A right side
HP 5212A gating neon light
HP 5212A test @ 550.53 kHz
HP 5212A test @ 9.9984 kHz
Posted April 30, 2018
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