Author Topic: Old Fluke Multimeters (Read 360763 times)

bd139 · « **Reply #675 on:** July 05, 2019, 07:16:16 am »

Plus if you’re burgled it doubles as a melee weapon

tautech · « **Reply #676 on:** July 05, 2019, 07:45:16 am »

Quote from: Pablitox on July 05, 2019, 05:43:29 am

The image I used was of mrmodemhead. This is the plate of my multimeter. It is somewhat blurred. Sorry for my lousy English

Your English is far better than that worthless blurry photo !
Upload a better one please.

Electro Detective · « **Reply #677 on:** July 05, 2019, 09:41:23 am »

The blurred image when flipped 180, and compared with previous image, sort of tells the story

'Perhaps' that board revision gave that cap a miss for whatever reason,

or the next stage didn't need it,

or... =

or need Mr. Taylor in on this one again

@Pablitox: does the meter work ok as is, and sort of agrees with another meter you have ?

rsjsouza · « **Reply #678 on:** July 05, 2019, 03:04:45 pm »

To me the difference between a concave and a convex solder blob may indicate the meter had a component soldered there at a certain point in time.

At any rate, the recommendation from the designer holds more water than any attempt to reconstruct the history of the device and find any potential reasons.

Pablitox · « **Reply #679 on:** July 05, 2019, 06:24:28 pm »

Apparently it is the version of the pcb
https://www.eevblog.com/forum/testgear/fluke-8060a-calibration-service/

Pablitox · « **Reply #680 on:** July 05, 2019, 06:26:14 pm »

I do not have another better camera

Change the electrolytic and clean with alcohol and air

Electro Detective · « **Reply #681 on:** July 05, 2019, 10:26:14 pm »

So apparently there should be no cap there ? perhaps cap compensation is elsewhere on the PCB as per Revision?

I would leave as is if the meter is working ok, and has been for years and years

I've come across gear before with blank or solder filled holes (...Dude, where's my cap?!

)

and just assumed they are there to solder in a component if necessary due to circuit/parts tolerances out of wack or ripple etc at assembly time

On the other hand, if it was a slimy penny pinching exercise to save .5 cents at manufacturing

and THAT circuit may/would benefit with no possible harm or CAL hit,
hey, give it a go

Pablitox · « **Reply #682 on:** July 06, 2019, 05:56:47 pm »

Quote from: Electro Detective on July 05, 2019, 10:26:14 pm

So apparently there should be no cap there ? perhaps cap compensation is elsewhere on the PCB as per Revision?

I would leave as is if the meter is working ok, and has been for years and years

I've come across gear before with blank or solder filled holes (...Dude, where's my cap?! )

and just assumed they are there to solder in a component if necessary due to circuit/parts tolerances out of wack or ripple etc at assembly time

On the other hand, if it was a slimy penny pinching exercise to save .5 cents at manufacturing and THAT circuit may/would benefit with no possible harm or CAL hit,
hey, give it a go

If something works well, do not touch.

And this Fluke 8060a works excellent. No calibration was necessary. I used it used

rsjsouza · « **Reply #683 on:** July 07, 2019, 12:47:56 am »

Well, I'll eat my hat. Both my 8060A and 8062A do not have this capacitor fitted.

8060A S/N: 4245166

8062A S/N: 4210192

The bad flux residue is due to my inexperience in properly cleaning boards at the time I recapped this meter.

The 8062A still has the original capacitors. None leaked, but it will go under surgery soon.

Electro Detective · « **Reply #684 on:** July 07, 2019, 11:06:10 am »

I'll have to crack open mine too asap

and hope I too am not a victim of the Fluke Cap Burglar

Alex P · « **Reply #685 on:** July 09, 2019, 06:21:43 pm »

Had a look at a few 806x meters:
8060A, s/n 4395401, pcb rev F: has the capacitor (IC date codes from 1982)
8060A, s/n (none seen), pcb rev H: does not have the capacitor (IC date codes from 1987)
8062A, s/n 5035011, pcb rev J: does not have the capacitor (IC date code from 1989)
Where the C is absent, the soldering islands look like straight from the factory, no sign of removal or additional soldering.

rsjsouza · « **Reply #686 on:** July 09, 2019, 07:31:06 pm »

I found in my hard disk some older downloads where I got the schematics and component placements and it seems the capacitor in question is C28: 10µF/16V in parallel with the zener voltage reference VRZ.

Why this was removed is a mystery, but perhaps it was suitable for stability?

Rev 1

Rev 3

Unfortunately the full scans are too large to be attached, so I did a search on the manuals and found that Mr ModemHead was kind enough to scan his copies and make them available at:
https://www.eevblog.com/forum/testgear/fluke-8060a-calibration-service/msg1462267/#msg1462267
(obviously he also mentions the C28 mystery)

Electro Detective · « **Reply #687 on:** July 10, 2019, 12:20:07 am »

Quote from: ModemHead on March 26, 2018, 12:38:58 pm

...C28 is a 10uF across the 1.2V bandgap reference. To be honest, I hadn't noticed that it disappeared at some point in the lifespan of the design. I have hardcopy documentation from 1983 and 1988.
C28 exists in the 1983 rev, but is not mentioned in the 1988 and the much-later PDFs available on-line from the Fluke archives.

If it is not in your meter then there should be no need to include it..

Let sleeping dawgs be for now,
well until more intel flows in..

IconicPCB · « **Reply #688 on:** July 10, 2019, 02:58:17 am »

Looking at the schematic the current for the zener is sourced via Z3 a 50K resistor.
It is possible electrolytic's leakage current may have been detrimental to the stability of the reference voltage.

I see no reason why a low leakage film capacitor could not be used there.

rsjsouza · « **Reply #689 on:** July 10, 2019, 10:39:36 am »

The issue there is space. If you want to keep the same 10uF that will take you to MLCC territory. How is leakage on these types of capacitors?

You could also derate its voltage for even less leakage (use 25V instead of 16V).

Edit: found some info at Murata, which places their MLCCs typically at 500MΩ-μF - this yields 50MΩ for a 10µF capacitor.

coromonadalix · « **Reply #690 on:** July 10, 2019, 10:46:09 am »

fluke 8060a, the 40 pins main ic could be an intersil 7106- 7107 series ??

bd139 · « **Reply #691 on:** July 10, 2019, 10:52:22 am »

It's a different IC. Similar design, at least from the 8000 flukes. I think the story is that Fluke developed the original IC with Intersil as a foundry and Intersil nicked part of it and sold the ICL7xxx series and Fluke weren't happy.

tautech · « **Reply #692 on:** July 10, 2019, 10:57:21 am »

Quote from: bd139 on July 10, 2019, 10:52:22 am

It's a different IC. Similar design, at least from the 8000 flukes. I think the story is that Fluke developed the original IC with Intersil as a foundry and Intersil nicked part of it and sold the ICL7xxx series and Fluke weren't happy.

Yep, info all about this in posts #1 and 17 of this thread.

rsjsouza · « **Reply #693 on:** July 10, 2019, 11:44:31 am »

Quote from: coromonadalix on July 10, 2019, 10:46:09 am

fluke 8060a, the 40 pins main ic could be an intersil 7106- 7107 series ??

Not at all. The 8060A has 20000 counts while the 7106/07 has only 2000 counts.

What tautech and bd139 mentioned is applicable for the 802x series.

IconicPCB · « **Reply #694 on:** July 10, 2019, 11:58:34 pm »

I think the original cap was an aluminium elctolytic and hence the comment on leakage current.

Electro Detective · « **Reply #695 on:** July 12, 2019, 10:50:47 pm »

I didn't know EEVblog host DJ did a cool test/quickie teardown of an RS badged 8060A during "EEVblog #802 - Mailbag" Youtube, 'published on Sep 28, 2015'

Not sure if that YT link has been posted here already

well, here it is again for those that missed it

youtube.com/watch?v=F_REyGWNAmc

or hit on the Mailbag page here on the forum that has the embedded? video > www.eevblog.com/forum/blog/eevblog-802-mailbag/?all

The entire Mailbag is a good watch (as they tend to be

) the 8060A feature kicks off about 3 minutes in, and runs for about 6 mins,

and yes 'That's A Knife' also does a cameo appearance

Please note: at about the 6.35 minute mark, clear evidence that pesky Fluke Cap Burglar rolled over that meter whilst in transit to DJ

AVGresponding · « **Reply #696 on:** July 21, 2019, 03:55:23 pm »

Recently scored an 8840A for the equivalent of around US$110, with the AC-09 option. Sadly no GPIB option, but meh...

The Micronta you see was my pride and joy, bought it new in '87 or '88, cost £70 which was half a weeks wage at the time, and added the shrouded sockets in '95 or so... safety first! 8-)

The Black Star is a recent add also, and has some issues... if there's anyone out there with good knowledge of the error codes on these, please pm me...

EEVblog · « **Reply #697 on:** July 29, 2019, 01:29:13 pm »

Quote from: ThickPhilM on July 21, 2019, 03:55:23 pm

The Micronta you see was my pride and joy, bought it new in '87 or '88, cost £70 which was half a weeks wage at the time, and added the shrouded sockets in '95 or so... safety first! 8-)

I lusted after that thing back in the day!

smmi · « **Reply #698 on:** August 01, 2019, 06:35:05 am »

hey Dave Taylor (if you're reading or see this)... you told me I needed to recap my 8060A, as I do plan to pass it onto my son...

I must lead a charmed life... 8060A (original owner) purchased new, in 1984 - used exclusively in my studio for cal, db and repairs... god bless audio-head meter engineers like yourself...

Meter specifics:
30-84 date code on the MAC @ U3...
serial number 3890330...
pcb revision H on the silkscreen... H-1 brown-tagged on the board...
also, C28, 10uF - is NOT populated on this board (per the later component list and schematic)...

Knowing that I needed to re-cap it, just because - I popped open the meter tonight (after ordering the parts) to see how many caps have let loose (assuming time did the inevitable) - and I'll be darned... not a single cap has leaked... still looks like a virgin... how weird...

In 35 years, this meter has never even looked at me funny... impressive... heck of a job...

btw, if you want to measure a set of intact 35 year old caps to see how much they've wandered (as these haven't imploded)... send me a pm and I'll send 'em to you...

you the man, Dave... Thanks...

ogdento · « **Reply #699 on:** August 07, 2019, 09:26:35 pm »

Hey Smmi that is great luck... they're much easier to re-cap when they haven't already made an awful mess!

I just opened up this guy and was excited to find my first ceramic MAC... aaand it's got capacitor puke on a few pins. I hope I don't wreck it pulling it out.


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Author Topic: Old Fluke Multimeters (Read 360763 times)

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