Dave does some performance checks and then tears down a Krohn Hite EDC 4601 0.05% 6 decade 1ppm resolution 0-1000V AC voltage standard.<br /><br />Service Manual with schematics: http://www.eevblog.com/files/4601ServiceManual.pdf<br /><br />MV106 DC Voltage Standard: https://www.youtube.com/watch?v=onqsjDJq4I0<br /><br />User manual: http://www.krohn-hite.com/htm/ServiceSupport/PDF/Manuals/4601%20Manual.pdf<br /><br />Datasheets:<br />Vactrol: http://www.excelitas.com/downloads/dts_vtl5c3c4.pdf<br />XR2228 Multiplier/Decoder: http://html.alldatasheet.com/html-pdf/119347/EXAR/XR-2228/96/1/XR-2228.html<br />Epson SPG8640 oscillator/divider: http://www5.epsondevice.com/en/quartz/tech/discon/epsondiscon/2000catalog/spg_8640series_e.pdf<br /><br />Forum: http://www.eevblog.com/forum/blog/eevblog-709-edc-4601-ac-voltage-standard-teardown/<br /><br />EEVblog Main Web Site: http://www.eevblog.com<br />The 2nd EEVblog Channel: http://www.youtube.com/EEVblog2<br /><br />Support the EEVblog through Patreon!<br />http://www.patreon.com/eevblog<br /><br />EEVblog Amazon Store (Dave gets a cut):<br />http://astore.amazon.com/eevblogstore-20<br />Donations:<br />http://www.eevblog.com/donations/<br />Projects:<br />http://www.eevblog.com/projects/<br />Electronics Info Wiki:<br />http://www.eevblog.com/wiki/