Fluke 760a Meter Calibrator teardown - Page 1
Forum section: electronics / testgear

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 04, 2013, 09:46:20 am
content: http://youtu.be/qFzYijK3LOwBleepin' huge. Awesome teardown though. So much fun.If ya got any answers to my questions then reply! I'd love to know some new stuff.Thanks!

author: Vgkid
author_rank: Super Contributor
timestamp: October 04, 2013, 05:47:22 pm
content: Have you tried probing the power supply when turning the knobs.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 04, 2013, 08:31:59 pm
content: haah no it not working was just a flimsy excuse to tear it apart completely

author: Vgkid
author_rank: Super Contributor
timestamp: October 04, 2013, 10:45:48 pm
content: The square cap(with arrow) at around the 21 min mark is a micamold capacitor. Im surprised at the noninductive (flat) resistors in the power supply. It looks like they wanted a really accurate voltage from those rails.

author: casinada
author_rank: Frequent Contributor
timestamp: October 05, 2013, 04:35:16 am
content: What you did is borderline criminal.Those straight cylinders on the switches are not capacitors, they're Fluke precision resistors. Those are big bucksNow challenge yourself and put it back togetheror design a circuit with today's technology that does the same thing(use microcontrollers, LCD display, analog switches, relays, etc)

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 05, 2013, 01:34:31 pm
content: ahhh okay. Yeah I guess that makes sense, how does it cancel out inductance?I don't have that kind of skill to do that, I'm an electrical engineer!

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 05, 2013, 01:40:05 pm
content: I was looking on ebay for those resistors, they sure are expensive! But its one of those things where people sell them for a lot but they are worthless because there is a tiny market for them. Same as selling a pentium-S processor on ebay, you can put it on there for like 7 bucks like everyone else, but there are already 20+ on there and they never sell.

author: Vgkid
author_rank: Super Contributor
timestamp: October 05, 2013, 06:10:10 pm
content: I'll take those resistors if you don't want them. about the meter, you have to remember that it was only a .05% accuracy on DC(best spec)Quote from: sonnytiger on October 05, 2013, 01:40:05 pmThe reason for less inductance is the smaller cross section, the more cross section, the more inductancehttp://www.rfcafe.com/references/electrical/inductance.htmrectanglehttp://www.technick.net/public/code/cp_dpage.php?aiocp_dp=util_inductance_rectangle

author: PA4TIM
author_rank: Super Contributor
timestamp: October 05, 2013, 08:00:24 pm
content: This is indeed bordeline criminal. I spend many hours in restoring mine to new condition . Such a waist of a fine calibrator. It is very versatile. It can do AC and DC to 1000V and 10A. The decades can be used for resistance calibrating. It is on paper worse as in practice. I use a 7.5 digit meter to monitor it but the null meter is then always spot on. The system with the nuldetector is very clever when calibrating current because it takes in acount the shunt used in the DUT.It is realy sad that you killed it

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 05, 2013, 10:58:34 pm
content: Well I sure am not losing any sleep over it. If you really want the resistors I can send them to you for postage or whatever. Just give me more details on what you want.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 05, 2013, 10:59:20 pm
content: Quote from: Vgkid on October 05, 2013, 06:10:10 pmWhat meter are you talking about?

author: Vgkid
author_rank: Super Contributor
timestamp: October 07, 2013, 01:01:45 am
content: Quote from: sonnytiger on October 05, 2013, 10:58:34 pmIs that directed towards me, I see you did a teardown of a Model M, a nice keyboard.

author: warp_foo
author_rank: Unknown
timestamp: October 07, 2013, 01:54:52 am
content: Quote from: PA4TIM on October 05, 2013, 08:00:24 pmYeah, that was a bit disappointing. This could have been a great repair video...m

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 07, 2013, 11:16:55 pm
content: I do not have the ability to repair this thing, I would have no idea where to start, and then I have no use for it, and extremely minimal space for stuff. I greatly enjoyed taking it apart. Also i know for a fact that that model M didn't work and there is only a single circuit board in it with no obvious problems. I still have most of the parts kicking around. I will admit I have a history of preferring to take things apart though... Maybe I should try differently next time an opportunity comes up. Thanks for all the comments by the way.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 07, 2013, 11:18:24 pm
content: Quote from: Vgkid on October 07, 2013, 01:01:45 amYes that was directed at you, not in an aggressive way though. What about the model M?

author: Vgkid
author_rank: Super Contributor
timestamp: October 08, 2013, 03:15:04 am
content: no worries about the agressiveness, those model M's have a really nice key feel(was on your YT chanel)Which resistors?

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 10, 2013, 12:41:23 am
content: Haven't really looked at them, if you know of any of them you want then tell me other wise I can give you numbers I suppose.

author: staxquad
author_rank: Frequent Contributor
timestamp: October 10, 2013, 06:30:21 pm
content: Quote from: casinada on October 05, 2013, 04:35:16 amhe's too giddy to do that presently

author: Vgkid
author_rank: Super Contributor
timestamp: October 10, 2013, 11:05:19 pm
content: Quote from: sonnytiger on October 10, 2013, 12:41:23 amI will take any that you don't want. Blue ones are the best.

author: staxquad
author_rank: Frequent Contributor
timestamp: October 11, 2013, 12:33:55 am
content: it's bad enough that you destroyed the calibrator, don't also destroy the 7 decade Kelvin Varley voltage divider, complete with high end switches and resistors, in cabinet, ready to use in another project

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 11, 2013, 12:46:17 am
content: Except I'll never use it. Why do you guys get yourself all in such a tizzy over what people are doing with their stuff?

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 11, 2013, 12:51:23 am
content: Quote from: Vgkid on October 10, 2013, 11:05:19 pmOk, by blue do you mean the aqua-green color?

author: codeboy2k
author_rank: Super Contributor
timestamp: October 11, 2013, 03:46:37 am
content: Quote from: staxquad on October 11, 2013, 12:33:55 amyes... I was preparing to cringe, and hoping that you wouldn't start clipping away at the KVD...Thank goodness that you saved it.. Now, don't clip those resistors (yes, the aquamarine, blue ones, or the square ones or anything else on the 7 switches...If you're in Vancouver, I'll come over and pick it right up

author: Vgkid
author_rank: Super Contributor
timestamp: October 11, 2013, 03:50:42 pm
content: I'm alright with codeboy taking the KVD resistors, I will take any other precision ones.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 15, 2013, 09:55:41 am
content: Sorry, kind of the opposite... I live in Nova ScotiaSomeone has already said they would buy the switch assemblies and the knobs, so unless he doesn't reply back then they are his.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: October 19, 2013, 03:37:53 pm
content: http://youtu.be/mq7Hy6iyJE8Short follow-up video.

author: n4buq
author_rank: Newbie
timestamp: June 27, 2020, 10:18:13 pm
content: Hi - Old thread but thought I'd ask anyway. Would you still happen to have any of the parts left over from the 760A? I'm interested in something from the front panel.Thanks,Barry