# Calibration & Repair with Ian Johnston

- Show: [The Amp Hour](https://hardwarepodcasts.com/podcast/the-amp-hour)
- Published: 2023-08-22
- Length: 1h 09m
- Episode: 643
- Page: https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston
- Listen: https://theamphour.com/643-calibration-repair-with-ian-johnston/

## Summary

Ian Johnston, a Scottish YouTuber and manufacturer, discusses his PDVS2mini DC Voltage Calibrator, explaining how he transitioned from the oil industry to full-time content creation and small-batch hardware production. He details the design evolution of the PDVS2mini, including component choices like the LM399 voltage reference and 20-bit DAC, and his manual assembly process for batches of ~50 units. Johnston also shares insights into his automated calibration workflow using a Keysight 3458A multimeter and his experiences sourcing and repairing test gear from eBay, including sales to high-profile clients like CERN.

## Chapters

- [0:00](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=0) Introduction: Ian Johnston and background
- [3:02](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=182) Workshop setup and transition to full-time YouTuber
- [8:34](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=514) Repairing Keysight U1272A multimeter OLED display
- [17:02](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=1022) PDVS2mini design history and component choices
- [18:57](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=1137) Manufacturing process: China enclosure and hand assembly
- [23:55](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=1435) CERN customer story and ADC testing for LHC magnets
- [27:38](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=1658) Automated calibration workflow and temperature control
- [37:52](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=2272) Keysight 3458A reliability and common failures
- [41:53](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=2513) Sourcing test gear from eBay and local deals
- [1:00:50](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-08-22-calibration-repair-with-ian-johnston#t=3650) Workshop organization and assembly decisions

## Topics

- [PCB design & layout](https://hardwarepodcasts.com/topic/pcb-design)
- [Test & measurement](https://hardwarepodcasts.com/topic/test-and-measurement)
- [Scaling production](https://hardwarepodcasts.com/topic/scaling-production)
- [Direct-to-consumer & e-commerce](https://hardwarepodcasts.com/topic/direct-to-consumer)
- [Sourcing & supply chain](https://hardwarepodcasts.com/topic/sourcing-and-supply-chain)
- [Careers & education](https://hardwarepodcasts.com/topic/engineering-careers-and-education)

## Most relevant to

early-stage companies

## Mentioned

- PDVS2mini (product)
- Keysight (company)
- U1272A (product)
- CERN (company)
- Keysight 3458A (product)
- LM399 (chip)
- ATmega328 (chip)
- eBay (other)

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- [069 - Canned Cheese and Onion Rings](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2024-04-17-069-canned-cheese-and-onion-rings) (Unnamed Reverse Engineering Podcast)
- [391: He’s the depressed, mean one](https://hardwarepodcasts.com/podcast/making-it/2023-03-10-391-hes-the-depressed-mean-one) (Making It)
- [317: What Do You Mean by Disintegrated?](https://hardwarepodcasts.com/podcast/embedded-fm/2020-01-17-317-what-do-you-mean-by-disintegrated) (Embedded.fm)
- [83: The First Time I Was Electrocuted](https://hardwarepodcasts.com/podcast/embedded-fm/2015-01-07-83-the-first-time-i-was-electrocuted) (Embedded.fm)

## Citing this page

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