Experiment with Keysight 3458A DC Reference replacement

attempts to replace DC voltage reference in Keysight 3458A DMM in pursuit of lower noise measurements for DCV function. 1:00 : Short lab update and new bench intro. 5:20 : Picking patient for surgery - standard Keysight 3458A DMM 10:00 : DMM disassembly 13:40 : New QVR Voltage reference design PCBA, Quad LTZ1000A on single board 17:50 : Removing original A9 LTZ1000A PCBA from 3458A 19:43 : Test fit with blank QVR PCB 23:45 : Butchering A1 DC board and cutting tall pin headers 35:00 : Close-up on QVR PCBA features 57:25 : Installing QVR module on 3458A's A1 board 1:00:00 : Setup modified 3458A for first power on and first failure 1:10:00 : Issue overview 1:20:30 : Removing connector and fixing issues 1:41:10 : Reinstalling QVR into meter for second attempt 1:43:20 : First readings with changed reference and self-test 2:03:30 : Connecting copper short for 3458A's zero calibration 2:16:00 : Calibration for 10VDC