HP 3458A "repair" and inner workings (Patreon)

HP 3458A - Why is this 31 year old Multimeter UNRIVALLED?

Participate in PCBWays 4th Design Contest https://www.pcbway.com/activity/4th-pcb-design-contest.html Subscribe to ExtraSolar https://www.youtube.com/channel/UCBzFZkWDp9g3jSWSOfk09MA My desoldering station https://www.banggood.com/custlink/vDmE68SdMz PCB holders from Welectron https://www.welectron.com/PCB-Holder HP Journal about 3458A https://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1989-04.pdf xDevs on 3458A https://xdevs.com/fix/hp3458a/ Fluke 732A over 1 Month http://reps.feste-ip.net:42545/dashboard/snapshot/ojS6RbJc94qxjved4R6auhhBVM0ivqtG Simulation: Dual slope integrating ADC https://tinyurl.com/yhcdn78z Simulation: 3458A Multisloper https://tinyurl.com/ye9xuu69 Simulation: AD637 RMS Converter https://tinyurl.com/ye572teb Simulation: Sample&Hold Frequency https://tinyurl.com/ydrxrovo 00:00 PCBway 01:27 Intro 03:34 First power on 05:08 History 06:55 Teardown 08:15 A1 Bboard 10:05 ADC theory 14:45 ADC in practice 16:20 ADC repair? 21:39 ADC error speculation 23:03 ADC success 24:34 AC error 25:35 AC basics 28:44 AC repair 32:37 Cable cap 33:19 Outgard PSU 33:47 Cooling fans 35:13 Mains filter 36:13 Plastic parts 36:44 Voltage reference 38:04 Digital board 39:29 Calibration 43:28 Results