HP 59313A Half Teardown

[amc184]

I bought this HP 59313A on eBay, not to use but as a really nice, yet reasonably priced, project case for a piece of test equipment I'm building.  These units are fairly obsolete, it's a four channel ADC with a max sample rate of 200Hz.  I'm not sure what the exact applications of these were back in their day, I think these were used as part of one of HP's automated spectrum analyzers.  This one is an option 001 model, 'hospital grey faceplate', so there might have been some sort of medical use (a common one too, option 001 units aren't rare).





I opened it up an found it was a classic eBay purchase.  There should be three large horizontal PCBs in this unit, the top and middle PCBs are missing as well as the riser board that connects them.  Oh well, I just wanted the case.





It's a classic unit of this era from HP, the build quality is really high.  Almost every IC inside has a proprietary HP part number, but I don't think any of it is custom, just customized labeling of off the shelf parts.  The bottom PCB has the input conditioning and switching, dual slope ADC and power supply.  The missing PCBs has the control and HPIB logic, and aren't that interesting anyway.







Interesting features of this unit are that the whole PCB is conformal spray coated apart from small masked off areas around the connectors and the epoxy dipped power transformer.  And here's what I was after, the stripped and cleaned case ready for a second life:

[TimNJ]

Love the design of old HP test equipment (and other manufacturers from this era). The style was short lived but it really was beautiful

[taylor12]

Great idea, do you happen to know what the output taps are on the transformer?

[TerraHertz]

Ha ha ha! That is a really good idea. For some reason, probably associated with my vintage-HP-cult-worship, it would never, ever have occurred to me. But now you mention it...

So, how much did that 'nice case' cost? Just curious.

Now I need to think of an ebay search term that finds old HP gear in nice cases, but useless models/vintage and dirt cheap.

[amc184]

@TimNJ: Yeah, so do I.  I'm not sure how long this style was around for, but there were a fair few instruments that used it.  The first ones that leap to mind are the 3312A signal generator and the 8903 audio analyser.

@taylor12: It has two centre tapped secondaries, first is about 18-0-18, second about 4-0-4 based on the rails they're used for.

@TerraHertz: Hey man, don't go buying them all up now!  I did initially feel a bit guilty about wrecking up a perfectly good instrument for the case, but if it's obsolete and no-one's going to use it then I'm really giving it a second chance.  Any lingering guilt was gone when it turned up with half the electronics missing, oh eBay....

I think I paid USD10 plus shipping (only to the US though, so cheap).  It wouldn't be such a great deal if I had to ship it back to here in NZ or Aussie though.  I'd just look for anything cheap using this case.  I've seen a few HPIB extenders and the occasional microwave amplifier.  Broken is fine too, as long as it's physically all right.  Just be careful, there's a few that look alright at first glance, but they're plastic.

[TerraHertz]

@TerraHertz: Hey man, don't go buying them all up now!  I did initially feel a bit guilty about wrecking up a perfectly good instrument for the case, but if it's obsolete and no-one's going to use it then I'm really giving it a second chance.  Any lingering guilt was gone when it turned up with half the electronics missing, oh eBay....

Not likely. After a small splurge in the last couple of days, I'm probably back to ebay window-shopping only for a while, due to empty wallet.

Another with that case but a bit deeper is the HP 59401A HPIB bus system analyzer - and those things are really annoying. Controls in Octal for a start.

I think I paid USD10 plus shipping (only to the US though, so cheap).  It wouldn't be such a great deal if I had to ship it back to here in NZ or Aussie though.  I'd just look for anything cheap using this case.
I've seen a few HPIB extenders and the occasional microwave amplifier.  Broken is fine too, as long as it's physically all right.  Just be careful, there's a few that look alright at first glance, but they're plastic.

So I guess what's needed is an ebay search term with a list of likely model numbers plus 'for parts' and sorted for lowest cost first.
Which gets us back to ebay's irritating 'follow' rubbish, and that you can't have saved search terms that don't clutter up your ebay landing page with hundreds of pictures you'd rather only see when you're actually doing a search. One of the most brain-dead things ebay ever did.