New Toy: HP 143 Wide-Screen Oscilloscope Mainframe Restoration – [Part 1]

At the risk of becoming a test equipment collector, I am picking up a few pieces of vintage test equipment that need some work, but will be very useful pieces of shop gear as well as interesting pieces of history lately. I’m needing a high speed analog X-Y monitor for some more complex alignments, and this old HP 143A oscilloscope came up on the local Craigslist for only a little more than the cost of the gas to drive and pick it up.

This is a really old school, transitional piece of gear. The CRT and mainframe assembly boasts all-transistor design, but the plug-in modules themselves are a mixture of tube, transitional nuvistor, transistors depending on the circuit position and the module’s capability.

They’re fairly rare, too, from what I can figure. A high school student in a family of engineers has one; a gentleman who did happen to be local had one earlier this year, and one configured with spectrum analyzer plugins is for sale reportedly removed from a Department of Defense HF monitoring station – a true cold war relic.

These wide-screen mainframes were a big ticket item back in the day, found in the HP scope catalog:

Adjusted for inflation, that’s very nearly a $10,000 CRT display – and don’t forget the options!

With what I’d consider the “base package”, add another $3,700 for the vertical amplifier and $3,100 for the timebase, you’re up to $17,000 for the instrument as shown below:

And the price only goes up from there! The mainframe supports some very high sensitivity (50 uV/div), differential, and high speed (GHz+) plugins – not to mention a frequency response generator, TDR, and spectrum analyzer that only go up get more expensive.

I’m lucky – all the knobs and switches are present. Those frequently get lost.

The HP Archive has good information about the scope including the operation manual and schematics. The plugins slide out easily:

Inside the timebase plugin, lots going on. Transistors and nuvistors together on this double-sided etched and silkscreened board:

Tubes on the other side of the enclosure, right next to some TO-92 package transistors.

Nuvistors were a very late-game evolution of the vacuum tube, and arguably held off the full transistor revolution for a few years.

Vintage really is beautiful.

This mainframe powers on successfully but doesn’t show a meaningful trace; it’s got some minor damage inside but should come back together nicely.

The vertical amplifier is pretty interesting inside, too:

This one has a mix of transistors, noval miniature tubes, and compactrons.

I’m looking forward to getting this one going again, but doubt I’ll be able to work on it before the end of the year.

Because this mainframe has identical vertical and horizontal amplifiers, the way to make it into an X-Y display is to use “vertical” amplifiers in both bays. If you have an HP 1402A plug-in for sale (or really, any other 1400-series HP plug-in), I’d love to hear about it.

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8 Responses to New Toy: HP 143 Wide-Screen Oscilloscope Mainframe Restoration – [Part 1]

  1. Mike says:

    I know this is an old thread but just ran across it and I have a 143a if any one is looking for one contact me

  2. Janis Winchester says:

    Do you have parts for a HP 1300A oscillascope? Thanks

  3. Jeremy Nichols says:

    I’ve had a 143A for several years and love it. No more squinting to see traces! The HP-1300A X-Y Display uses the same CRT if you ever need a replacement. The 143A is indeed quite rare because of its size, weight, and original cost.


  4. Pingback: Test Equipment Round-Up – September 20th, 2014 | KF7LZE's Blog

  5. Pingback: HP 1405A Plug-In Mystery: Which Is It? | KF7LZE's Blog

  6. steve says:

    Hello J.W., I saw this site when I punched in hp 143 this fine sunday morning. This is GREAT stuff!!! Fantastic! What is for dinner? I made some grilled tilapia in tinfoil with butter and mex lime juice from my tree. Wish you were here! My best friend, Nahum, just brought his wife over from mexico last night for the first time. They got her papers last week after years and years of trying. Hopefully, he and his family will come help me eat this fire baked potato and the fish today.
    I’m going to keep looking for the 1402a plugin. Cold war…that’s so cool!

  7. Pingback: Wanted: Vintage HP 1400-Series Vertical Amplifier Plug-Ins for Oscilloscope | KF7LZE's Blog

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