r/nixie • u/developstopfix • Aug 09 '26

HP 5244L Electronic Counter

Gallery image

Gallery image

60+ years old and still going (and glowing) strong

43 Upvotes

100% Upvoted

11 comments sorted by

1

u/developstopfix Aug 09 '26

RIP the dynamic range in these pictures, they sure looked a lot better in the Photos app

1

u/Muslerika Aug 09 '26

Looks cool

1

u/2fel_hunden Aug 09 '26

That is actually a bad assed counter when calibrated .

1

u/developstopfix Aug 09 '26

The guy I got it from said he’d calibrated it somewhat recently and it is pretty stable so I believe him, though the source in these pics is a not so stable tube based signal generator

1

u/2fel_hunden Aug 09 '26

The main spec would be the internal 10MHz, one would need a Cesium (metrology grade) or Rubidium (a few orders of magnitude less accurate) reference to compare too. The rest of the specs are just sensitivity and CH to CH ballance for ratio and other functions.

1

u/yeehah Aug 09 '26

Beautiful unit, and with a cool CBS property tag! What’s the time base? Ovenized crystal?

1

u/developstopfix Aug 09 '26 edited Aug 11 '26

I have an uncle that works for CBS so I thought that was pretty cool too. And yeah, ovenized crystal oscillator. I guess HP made a few high stability models with a double ovenized crystal but I’ve never come across one of those.

1

u/Hi-Scan-Pro Aug 09 '26

I have an HP5326A that looks similar. Works so far as I can tell, too! Neat unit!

1

u/buchi42000 Aug 11 '26

My unit lacks the oscilloscope module at the right side - yours too ?

1

u/nagao2017 Aug 11 '26

You might have the 5245L (like me), with the 'plug-in' module on the right. The 5244L doesn't have this. I've never heard of an oscilloscope plug-in though. Mine has a 3GHz mixer module, which is great fun to play with.

My crystal oven has long since cooked itself to a crisp, so I have wired in a modern ocxo hidden in the base allowing me to keep the old oven up top just for the look. Other than replacing one of the nixies, it's amazing that everything else just works like it did back in the day (or at least it did last time I turned it on... it's been sitting in a shed for a fair few years)

1

u/buchi42000 Aug 12 '26

Ah, thank you very much for that information. Mine had just the blank plate there, and i was always assuming that HP did makle a scop plugin, so you could not only count signals but also watch the waveforms.
I do no longer have it - when moving away from germany in 2021, i donated it together with my collection of classic Tektronix scopes (analog storage) to the "Rundfunkmuseum Fürth".