Old Fluke Multimeters

[drtaylor]

Message to Dave: I worked at Fluke in the late 70s and early 80s as a design engineer. I started as a junior engineer on the original handheld DMM, the 8020. Later I was the chief designer of the very successful 8060 series, which by the way, was the first microcontroller based handheld DMM. Anyway, I have many Fluke DMMs that are gathering dust, and I wonder if you'd like them for your DMM collection? Most of them still work or just need minor repairs. Some of them are original hard model units, that is pre-production models. At one time I had a box of 30 or so 8060s that had a minor programming error, but otherwise worked fine. 8060s were cool for audio as they had dB conversion and a wide band (at least for the time, 100kHz) true RMS converter. I used to give them to friends, most notably, I gave one to my dear departed friend Jim Williams. Anyway, I have some of the first generation handhelds, 8020, 8026, 8060, 8062, benchtop versions 8012A, 37, and an 8920 Wideband TRMS AC Voltmeter that used a thermal converter. I also have a lot of vintage parts for various Fluke DMMs.

It probably isn't widely known anymore, but the A/D in the Fluke 8020 was developed in a joint venture with Intersil. Then Intersil decided to market it to the world by making a tiny change to get around exclusivity...lawsuits ensued. The Intersil version is still available...the venerable ICL7106 and the LED version which Fluke never used, the ICL7107. When we started on the 8060, Fluke decided they had to have their own silicon fab to keep Intersil from getting our 4 1/2 digit design. Good times, perhaps a bad business decision on Fluke's part since they ended being stuck with an obsolete process and couldn't justify the numbers necessary to update it. The original TRMS chip used in the 8060 was designed by Fluke guru Norm Strong and developed in a joint venture with Motorola (when they were just a silicon company).

Let me know, my wife would be glad to be rid of them.

[edavid]

Did you work on the 8040A?  That's my favorite, although it's not very practical.

[Mr Simpleton]

 

[Kryoclasm]

Used Fluke DMM's in the US Air Force for years, love them.
They really spoiled me, now I compare all DMM's to Fluke.

[poida_pie]

paging Mr Modemhead !

You need to see this.

[Excavatoree]

paging Mr Modemhead !

You need to see this.

And Retiredcaps.

Wow.  Thanks for joining and posting.  I'm sort of partial to old Fluke meters, myself.

Now I know why some of the ICs I've seen were labeled Intersil.

[Napalm2002]

I have two 8020 a's two 8020b's an 8024 two 8060a's and an 8062. That all work and I love em. I could use a 8020a LCD if u have two laying around. I have two meters that need them and would love to fix them. If u have an 8060 that u would like to sell I would be interested...

Any more history or fluke trivia would be appreciated. I'm sure that I speak for all of us that we would love to hear it!

[HackedFridgeMagnet]

Let me know, my wife would be glad to be rid of them.

Spare a thought for Dave's wife.

[Excavatoree]

I don't know anyone who collects these meters that doesn't need an 8020 LCD.   The meters continue to outlast the LCDs.

[Dave]

I would love to see them torn down side-by-side, so we can see how their designs advanced through the years. I already got excited just thinking about it. Make this happen!

[Excavatoree]

One question:  Was there any significant difference between the IBM branded 8060 and the "regular" one?

[SLJ]

Interesting information.  I talked to a retired Fluke 8020 production manager last week.
My first DMM was a 8020A,  Here's some pics of mine:

http://www.stevenjohnson.com/dmm.htm

Not enough for a Fluke page yet though.

[ModemHead]

paging Mr Modemhead !

You need to see this.

Here! 

It probably isn't widely known anymore, but the A/D in the Fluke 8020 was developed in a joint venture with Intersil. Then Intersil decided to market it to the world by making a tiny change to get around exclusivity...lawsuits ensued.

Thanks for clearing up the relationship of the ubiquitous ICL7106 and Fluke PN 429100.  That has always been a mystery to me!

[Attorney]

Later I was the chief designer of the very successful 8060 series...

The 8060A is the greatest handheld DMM of all time.

Paul

[lowimpedance]

Fantastic info.    , I wonder what that small change was!.
I have successfully transplanted an ICL7106 into an 8012a with no issues.
 Its still pleasing to see there are many 8020's and others in the series still out there.
I have two which sport 'new fitted LCD's' , that still get regular use.
I have many meters but my venerable old fluke 77 is still my most used ,(will have to be pried out of my cold dead fingers with a crow bar).


I just hope they go to a good home and not landfill.

Let me know, my wife would be glad to be rid of them.

[grenert]

Later I was the chief designer of the very successful 8060 series...

The 8060A is the greatest handheld DMM of all time.

Paul

I am totally with you on that. 
You certainly wouldn't want to take an 8060A to a harsh environment, but for a bench-bound handheld, it is awesome.
Great work, drtaylor!!! (but I'm sure you already knew that)

[retiredcaps]

Message to Dave: I worked at Fluke in the late 70s and early 80s as a design engineer. I started as a junior engineer on the original handheld DMM, the 8020. Later I was the chief designer of the very successful 8060 series, which by the way, was the first microcontroller based handheld DMM.

To Dave and Chris,

I for one would LOVE to have drtaylor on the amphour (or two or three) as a guest. 

To drtaylor,

We would love to hear more history about how these multimeters came to be and all your war stories. 

[drtaylor]

To Attorney and grenart: Thank you, I thought so at the time too. It was definitely my most successful and satisfying design throughout my career. The original spec just called out for a 4 1/2 digit handheld with TRMS ac. I am an audiophile and used to play in bands, so I wanted a meter with dB and at least 100kHz bandwidth. I added a lot of features to the original spec which required a microcontroller. At the time, the only CMOS micro you could buy was CMOS versions of the 8049. Huge package and not all that capable. Then the SW engineer and I came across some literature about the Sharp SM4. Mostly used in calculators. Perfect...multiplex LCD drive and sufficient power to run the A/D chip and do the dB conversions. At the time, Fluke Sr was against using Japanese components and it fell to me to convince John that it was worth it. Fluke subsequently had a long relationship with Sharp. They also made the custom LCD. BTW I did the layout and multiplex scheme for the LCD segments too. Hand drawn on graph paper. Pre CAD. Somewhere I have the original hand drawn schematic of the 8060. Norm Strong designed the Silicon for the A/D and the TRMS converter, and Tom Wiseman was the software engineer and I was the hardware designer and project manager and provided all the text for the User Guide. Tragically my good friend Tom died a few years later mountain climbing here in Washington state.

To loimpedance: The only difference between the 8020 converter and the ICL7106 was that the Fluke chip electronically switches between 2V FS and 200mV FS, whereas the 7106 requires circuitry changes to accomplish the same. I'm curious how you got the 200mV range to work on your 8012A. The 8010a and 8012a multimeters were just repackaged 8020s for benchtop use. The 8012 added a 2 ohm and 20 ohm range with a pot to trim out lead resistance.

Someone asked about the 8040, it was in production about a year before I arrived at Fluke and I had nothing to do with it. It didn't last too long as the 8060 was a huge success  and significantly cheaper. The 8040s biggest problem was LED noise coming out the banana jacks limiting low level AC readings. But otherwise a fine DMM.

Regarding 8020 LCDs, I might have a few, I'll check. Even in storage though, the polarizer would delaminate or depolarize and the effect being a black screen. I have revived a few bad old Crystaloid 8020 LCDs by peeling off the front polarizer and using a loose one cut to size. I think I have more 8060 LCDs but they've been sitting in a bin for years.

To Excavatoree: There is no difference in the IBM version and the standard 8060 other than case color and label. The design of the 8060 was modified while it was in development to meet an IBM requirement. That brings up another story - I traveled to IBM in East Fishkill NY to firm up their requirements. I was accompanied by the local Fluke Rep, who basically just sat there while I discussed the technical requirements, as well as the custom color and label. This turned into the largest single sale in Fluke history at the time. I think they bought 10000 units. I and the SW Engineer Tom were personally thanked by John Fluke himself. Later I returned for a followup visit to IBM, the Rep (who had just sat there) took me out on his new yacht. So the score was Rep 1 (new yacht), hard working engineer who conceived, executed, and delivered the 8060, 0 (and an attaboy). That's when I realized the engineers place in the world. BTW I have a few IBM blue cases in my junk drawer (unless the wife got to them).

I have a list somewhere of 8060 tricks, but one I remember off the top of my head, because I spent a lot of time designing that switch array to do it... If you pop out the two bottom switches, the input is connected directly to the A/D and the 10M divider network is disconnected. Therefore, like far more expensive DMMs, you get near infinite input impedance. Works only on the 200mVdc and 2Vdc ranges of course. But useful for those times when you don't want to load the circuit with 10M ohms. The calibration shifts slightly, but relative accuracy it great with absolutely no circuit loading.

A little more on the Intersil 7106. When Intersil first announced the 7106 to the world, we stripped down the die. It still had the Fluke logo in microwriting on the die. They didn't even change that. Anyway Fluke was in a tough situation since it depended on Intersil for the 8020 and subsequent similar designs. In the end the lawsuit was settled for price concessions. We also were to receive the References free as a concession.

Too long a post, but feel free to ask any questions. I have a few more "war stories" that I'll share someday, but in conclusion, working at Fluke was a great experience and I learned a lot from some really talented engineers. I don't know if I'd be happy there now since they were acquired by Danaher, but it was a great place to work back then.

[Attorney]

...I am an audiophile and used to play in bands, so I wanted a meter with dB and at least 100kHz bandwidth. I added a lot of features to the original spec which required a microcontroller.

In a prior life, back in the early/mid-80s, I was an engineer at RKO Radio in Chicago.   It was a gig right out of college.   For two years, my boss and I led the design of many specialized audio and control projects.  But the one project designed that made extensive use of the 8060A was a precision (10, 1, 0.1 dB), ultra-low-distortion active attenuator that fit into a Tektronix TM series frame.  We needed a way to attenuate audio from the low-distortion/low noise output of a balanced Tektronix SG505 oscillator.  To accomplish that goal, we used a new active attenuator chip (at the time) from Analog Devices.  To test its accuracy, we relied solely on the 8060A.  For noise measurements, we did rely on a Tektronix AA-501A analyzer that was cross-checked with the 8060A.   As I recall, the 8060A in its lowest AC position is good down to about -74 dBm.  It sure may not be specified down that low, but it absolutely works down there.

Of all the test gear we used at RKO, the 8060A was without a doubt the most valuable to us.  It made such an impression on me that I've used them for the past thirty years.  It actually caused me to detest auto-ranging DMMs due to their long hunt times.  When I can find a NOS 8060A, my bid is in there.

Thanks for the design of the 8060A.  I have to believe the lives of many folks like myself were made easier by its availability.

Paul

[PA4TIM]

I have a 8022, the display was dead but Conrad or Farnell (can not remember)  sells a display + 7107 for a few bucks. I used that display
http://www.pa4tim.nl/?p=787 to restore the 8022 (see link)

I have a 77-III, a 845AB,, a 8000 with 20A option and some cal stuff:  750, 760, 720, 332, 731, 535
I spend a lot of time restoring a 8500 with all documentation incl docs from training course an brochures. To bad it did not last, the controller died and I parted it. It had many option including the TRMS converter that was a piece of art. Very large crest factor and bandwidth.

[retiredcaps]

It was definitely my most successful and satisfying design throughout my career.

What other projects have you worked on?

I was the hardware designer and project manager and provided all the text for the User Guide.

I'm just learning more about how multimeters work over the last 12 months, but last year I managed to get a poorly worded ebay auction that landed me a non working IBM 8060A with two copies of the instruction manual.  I have read the manual over and over and each time I learn a bit more. Thank you for writing a clear easy to understand manual.  The troubleshooting chart, BOM, schematics and theory of operation are invaluable.  You certainly won't find this level of detail anymore today in any handheld meter.

My non working IBM 8060A was due to several bad capacitors.  Not really surprising given the IBM 8060A is probably 25 years or older. 

Modemhead found bad capacitors on his too and documented the whole troubleshooting process at

http://mrmodemhead.com/blog/fluke-8060a-repair/

Other than the capacitors, the 8060A seems to hold up very well in terms of reliability and accuracy.

So the score was Rep 1 (new yacht), hard working engineer who conceived, executed, and delivered the 8060, 0 (and an attaboy). That's when I realized the engineers place in the world.

Without going into details, I have been in the same situation where one year we were the number #1 sales team worldwide.  The Sales Rep got fifteen times (15x) in commi$$ion compen$ation compared to what I (technical) made in salary.  I didn't even get an attaboy.  After that, many technical engineers made the jump to Sales which left with huge holes in the technical department.

I have to give some credit to my Sales Rep though.  I mean, someone, has to take the customer to expensive dinners with fine wine, golfing, trips to HQ followed by more aforementioned activities.

A little more on the Intersil 7106.

How do you feel about all the $5 or less generic 830 style case multimeters using the 7106/equivalent.  In terms of accuracy, 0.5% on DCV, they seem to hold up well.

in conclusion, working at Fluke was a great experience and I learned a lot from some really talented engineers. I don't know if I'd be happy there now since they were acquired by Danaher, but it was a great place to work back then.

I feel the same about my former company.

[drtaylor]

To retired caps,

At Fluke I worked on the 8020A, 8020B, 8024B, 8026B, 8010A, 8012A, 8920, 8922, and a few miscellaneous projects. I spend a lot of time developing a Digital Readout Power Supply, at the time quite innovative, but Fluke decided that HP (now Agilent) dominated that market and dropped the project. I still have the prototype. BTW, that was the project that was to use the LED version of the 8020 chip, AKA the ICL7107. Then came the 8060, 8062 and the IBM 8060. I left Fluke after the 8060, although I was working on the 77 A/D converter and TRMS converter. But the 77 came out after I left for Wavetek. At Wavetek I developed the model 52 DataMultimeter. Worked well but Wavetek couldn't crack the DMM market. I also contributed on Arbitrary Waveform Generators at Wavetek and was the Engineering Manager of the Function Generator department. After 5 years at Wavetek I saw the writing on the wall that they were going under (that's what happens when you let marketing guys run a tech company and they try to grow by buying companies without managing to keep the key people). Ever since then I design digital weigh scales for a small company MSI (who was just bought by a big scale company, Rice Lake).

Regarding the caps. No doubt those were the electrolytic caps in the 7660 Charge Pump circuit that I used to generate the negative rail for the TRMS converter and the A/D. Aluminum Caps do age, and I wish I could leave them out, but Tant caps there were deemed too expensive. So change those electrolytics and the 8060 will probably work for another 30 years.

Another feature of the 8060 I was proud of was that it was the first DMM to have truly fast continuity. A separate hi speed comparator was added to the A/D silicon expressly for this purpose. It doesn't depend on a conversion. I rate almost all DMMs by hitting the probes together as fast as I can. A fast continuity will beep. I'm surprised how many DMMs designers still don't get how important this is in troubleshooting. I recall the 8024 might have had fairly fast continuity, but it was external to the A/D.

The 8060 had a remarkably long run at Fluke. It was only retired finally in, if I remember correctly, around 1995. I was disappointed they didn't find me for a retirement party.

This has been a fun trip down memory lane. Thanks to all.

[ModemHead]

I find this absolutely fascinating.  Thanks much for taking the time to post.

As for my previously noted 8060A repair, yes indeed the 7660 charge pump caps were gone, plus some others had effectively destroyed the MAC socket.  The final problem was some current leakage that resulted in a non-zero idle reading that was cured by substituting another MAC chip. Until I got the bright idea to scrub the original MAC with IPA, after which it also worked perfectly.

I recently acquired my second 8060A.  A simple cleaning of the elastomeric connectors brought the unit back to life.  Calibration still spot on.  A very nice instrument.

BTW, other than the electrolytic caps, it seems the other most common defect is missing buttons.  Somebody was selling them on eBay recently for $6 apiece!

My question: Did Fluke originate the side push-button/angled-display handheld design?  There seem to be quite a few from the era with a curiously similar appearance.  Weston comes to mind.

[BravoV]

drtaylor, please, post few photos of those never released prototypes at the DMM collection thread here -> Show your Multimeter! , it will be very unique entry there. 

[Napalm2002]

Great info and story's. I
Would very much like a blue case to an 8060a if u have one! Got any more trivia in there? ...