Category: Test Gear
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HP 6060B System DC Electronic Load: Adjustment
Currently, the unit’s setpoint accuracy isn’t all that great (readback resolution is limited as well, but shows the offset): Regardless of the range it has an offset of about +20 mA. Sure, for a unit capable of 60 A that seems reasonable, and well within its specs of ±0.1% ±75 mA. But since I’ll use…
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HP 6060B System DC Electronic Load: Teardown, Service
I recently got my hands on a HP 6060B System DC Electronic Load (later also sold as Agilent 6060B). My unit has option 020 installed: Comically large binding posts also on the front panel. This option certainly is not unheard of, but not too common either. Retrofitting is possible, but can be quite some work.…
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HP Instrument feet
Many older HP/Agilent instrument share a similar feet design. There are at least two different types though: One with a metal part to prop up the instrument and one without it that can be used on all four corners. The feet can be detached from the instrument, e. g. for use in 19″ racks. This…
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Brymen BM789: Not a Review
Almost two years ago I bought a Brymen BM789 Multimeter. And there is a lot to like about it. It has great specs, is feature-packed, feels high-quality and yet it’s well priced. But there are also some mostly minor aspects I don’t like: My main issue though and this is not limited to Brymen (hello…
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Agilent 34401A repair
The other day I noticed an issue with one of my Agilent 34401A’s: I measured a constant DC voltage and after a few minutes the measured value would start dropping and become unstable. Then I got curious and checked the two-wire resistance mode. Same story, maybe worse. A word of caution: High voltages found inside…
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Tektronix 465B: Repair
For engineers analog oscilloscopes are a bit like vinyls and tube amplifiers: Most don’t use them anymore, but if they see one, they think: Nice! And are happy that they don’t have to deal with them on a daily basis 😉 However, I bought a Tektronix 465B with a faulty second channel, just to repair…
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HP 5328B Universal Counter: Mini repair
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.…
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Siemens B2086 Decade Resistor: Calibration
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. I couldn’t find a date code on it. However, back in the day they published proper manuals including…
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Precision Resistors
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…