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  HP 5328B Universal Counter: Mini Repair

  February 10, 2023

  The HP 5328 series counters are a range of 0 to 100 MHz Universal counter from the 70’s. While fairly similar on the outside, internally the updated B model differs from the A model significantly. The HP 5328B’s build quality impresses still today - even for the front panel they didn’t use plastic back then. Its specs however don’t. The direct count measurement provides a resolution of up to 8 digits/s, far less than modern but much more expensive reciprocal counters (with an interpolator) achieve. In my configuration the counter features an 8 digit LED display. In contrast to most newer counters the HP 5328B has dedicated marker outputs (trigger outputs) for each channel on the front panel.

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  Programmable Decade Resistor: Topology (1)

  February 7, 2023

  In this post I want to share how I selected a suitable topology for the resistor network that will be the core of the programmable decade resistor. Although I did some online “research”, the following criteria determined my choices:

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  Siemens B2086 Decade Resistor: Calibration

  February 4, 2023

  I briefly mentioned the Siemens B2086 Decade Resistor in the previous post. In this post I want to provide additional information on this interesting “vintage” unit, which seems to be geared towards AC application, not just DC.

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  Progammable Decade Resistor: Intro

  February 4, 2023

  In 2021/2022 I designed a DC electronic load that would be more capable, but also much more complex than the usual DIY solutions. However, after building a working breadboard prototype of the analog circuitry with 12 ICs including multiple precision and dual opamps, I thought that it might be better to start with a smaller project that would allow me to gain a lot of experience and write much of the non-application specific code that I could use later on for the digital part.

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  Precision Resistors

  February 4, 2023

  With the availability of affordable precision resistors it has become fairly easy to build a diy “resistance standard” that is more than good enough for (most) hobby use cases, e. g. checking DMMs and comparing them with each other. So a while ago I built a simple enclosure for such a precision resistor with 4-Wire (4W) measurement terminals.

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  Fluke 175: Repair

  February 3, 2023

  I recently scored two Fluke 175 multimeters that were sold on ebay as a set waiting for repair. According to the seller, the first multimeter was fully functional except for the beeper. The second meter had a strange error rendering it unusable, but came with a working beeper. The sellers suggestion then was to transfer the known-good beeper to the first meter.

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  Yet Another Nixie Clock

  February 2, 2023

  I‘ve always been fascinated by lights and all kinds of displays. Nixie tubes certainly are no exception. So I had to built my own Nixie clock as probably every EE does. Caution