HP 3466A quick teardown and clean-up - Page 1
Forum section: electronics / testgear

author: ealex
author_rank: Frequent Contributor
timestamp: July 30, 2013, 09:05:43 am
content: HelloHere are some photos of a "new" HP3466A multimeter:The date codes on the chips are around 22'th week of 1986.It was very clean inside and I only had to apply some contact cleaner on the function switches - they were intermittentDo you know where i can find some end-caps for the range switches ? one of them is missing.Also, i don't have a clue where to find some appropriate test leads, the standard ones don't fit and making a set from scratch does not seem such a good ideea.Next step will be to find some sort of reference supply to test it against.

author: macboy
author_rank: Super Contributor
timestamp: July 30, 2013, 12:07:44 pm
content: This meter appears to use standard banana jacks. Most test leads you can buy have banana plugs, but with a safety sheath to prevent accidental contact should the lead get pulled out of the instrument while connected to something. You can usually trim off that sheath, then it becomes a basic banana plug. Obviously this should only be done if you are using the leads with an instrument with jacks like this, and make certain that the plugs fit do snuggly to prevent accidents.I am curious, why do you say you need a "reference supply" to test this meter? You appear to have a 34401A on your bench. Its precision and accuracy are plenty good enough to verify this instrument (it is 10x as accurate and 100x as precise). Connect any arbitrary but stable voltage to both meters simutaneously and compare. Repeat for all ranges. For ohms, you don't connect simutaneously obviously.

author: ealex
author_rank: Frequent Contributor
timestamp: July 31, 2013, 06:35:48 am
content: I'll try to alter some standard probes.The 34401A is not calibrated - I have no idea if it can be trusted.I've played around with some batteries and at least the low voltage range seems to work properly.Maybe it's better to just start using it and testing features as i need them, measuring against the 34401A - it's too much of a hassle getting access to proper equipment.

author: valentinc
author_rank: Regular Contributor
timestamp: August 01, 2013, 09:04:10 am
content: If you want some good cheap test leads, I recommend the UNI-T UTL16,http://dx.com/p/utl16-multimeter-test-lead-cable-red-black-2-pcs-150417which you can get at about $16...You can build yourself a very cheap voltage reference (which would be preety stable with temperature, more stable than let's say a battery... of course this can be only for comparative measurements... It's not suitable for this type of application) with the TL431...Can you take some pictures under the shielded input section ?

author: ealex
author_rank: Frequent Contributor
timestamp: August 04, 2013, 03:28:55 pm
content: @valentic: sorry, but I will not open it again, it's not very straight forward and I do not want to disturb some sensitive parts if there is no need.

author: w9gb
author_rank: Contributor
timestamp: October 20, 2013, 12:11:21 am
content: Push Button Switches (and Caps) used on the HP 3466A.Schadow Switches (German manufactured) were very popular in 1970s and 1980s.http://www.wellgainelectronics.com/s...tonswitch.aspxSchadow even had an interlocking vision (flag) switch. Schadow became part of ITT.ITT became C&K Switch.A common problem with these switches is that the tiny spring (inside the mechanism) breaks.It can be repaired by replacing that specific spring.Mouser and Digi Key stock theC&K Switch F-series pushbuttons.http://www.ck-components.comMouser catalog pagehttp://www.mouser.com/catalog/645/usd/1801.pdfDigi-Key catalog pagehttp://www.digikey.com/catalog/en/partgroup/f-series/8826E-switch discontinued their "clone" versions of these switches a few years ago (TA-series).Switchcraft has similar DW multi-switch serieshttp://www.switchcraft.com/Category.aspx?Parent=655Replacement F-Series buttons (Standard, not custom designs) are available from C&K Switch.Black, White, Red, and Light Gray are Standard Colors.http://www.ck-components.com/13342/fpush_31aug10.pdf/C&K Components15 Riverdale AvenueNewton MA 02458USATel: +1-617.969.3700http://www.ck-components.com/switches-supplier.html