Author Topic: Old Fluke Multimeters  (Read 216059 times)

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Online med6753

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Re: Old Fluke Multimeters
« Reply #725 on: January 10, 2020, 10:33:57 am »
Out of all the classic vintage Fluke meters, which ones are more / most reliable, accurate and easy to repair?

I have a Fluke 25 from 1980s, it is still being used daily.
I just bought a Fluke 8000A in very poor cosmetic condition and with unknown working condition.
Will have to be tested, and repaired if needed.

It's really a crap shoot. Depends on how much use/abuse they received. I have an 8000A, two 8800A's, 8600A, 8010A, and 8050A. At the very least you should expect to re-cap the power supply. And then perform a calibration. 

The 8000A is a decent 3.5 digit DMM but at least mine suffered from some drift issues. For some reason Fluke decided that the +5V supply didn't need to be regulated. I fixed that by re-designing the power supply. If you want the details of what I did let me know. 
An old gray beard with an attitude.
 

Offline vinlove

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Re: Old Fluke Multimeters
« Reply #726 on: January 11, 2020, 02:31:00 pm »
My 8000A has a lot of problems. I had opened separate thread for it.
It would be really cool if it works with reasonably accuracy.

Maybe it needs full recap, and upgrade of the PSU?
 

Offline Martin.M

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Re: Old Fluke Multimeters
« Reply #727 on: January 12, 2020, 07:38:38 am »
8300A Nixie Fluke. Options 1+2 (  mV/Ohms card + AC card)

I found a problem:

DC Test: OK
AC Test: OK
mV Test: OK
Ohms: to low + floating

dou you have a tip for me?

mV is common used with Ohm, so this part is allready working. It can be anything around the current source what is required to test resistors.

greetings from germany
Martin

edited:

Range switches kOhm:

1000 works
100 works
10 fail
1 fail

it can be interconnection, or the A3 transistor array what drives the both reed relays. on the mV Ohms card.
« Last Edit: January 12, 2020, 08:36:05 am by Martin.M »
 

Offline tautech

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Re: Old Fluke Multimeters
« Reply #728 on: January 12, 2020, 10:06:29 am »
8300A Nixie Fluke. Options 1+2 (  mV/Ohms card + AC card)

I found a problem:

DC Test: OK
AC Test: OK
mV Test: OK
Ohms: to low + floating

dou you have a tip for me?

mV is common used with Ohm, so this part is allready working. It can be anything around the current source what is required to test resistors.

greetings from germany
Martin

edited:

Range switches kOhm:

1000 works
100 works
10 fail
1 fail

it can be interconnection, or the A3 transistor array what drives the both reed relays. on the mV Ohms card.
Check them, they do give up after years.
Member Defpom had trouble with one in his Tek 851.
IIRC it was in Pt2 of 3
Avid Rabid Hobbyist
 

Offline Martin.M

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Re: Old Fluke Multimeters
« Reply #729 on: January 12, 2020, 10:20:35 am »
found it: a bad gold pin. will be replaced by one from TP  ;)
 

Offline MarkMLl

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Re: Old Fluke Multimeters
« Reply #730 on: March 08, 2020, 01:46:14 pm »
Member Defpom had trouble with one in his Tek 851.

Thanks for that link: the infamous BDM ("Burroughs Digital Meter") 1250. Just by chance I spotted this a few days ago, referring to a predecessor instrument (BDM 1200) which I'd not previously come across:

https://www.ebay.co.uk/itm/383449915730?ViewItem=&item=383449915730

A number of people discussing these things bemoan the fact that they didn't have a CRT for even minimal 'scope functionality. The background however is that while field engineers were expected to do component-level repairs the factories producing the various computers were expected to also produce a set of Maintenance Test Routine (MTR) procedures, and while some of these were based on software and others assumed the availability of a special card tester (carried by the higher-grade FEs) others "simply" had the instructions to put the hardware into such-and-such a state and then count the number of pulses at such-and-such a point when a button was pressed. Hence the various counting functions visible on both the BDM 1250 and the earlier BDM 1200 photos.

Of course, some of this method of faultfinding was inspired by the fact that many of the electromechanical terminals and accounting systems had serial ALUs, with their main memory being a small head-per-track disc drive. This sort of thing was sold in large quantities into banks: even the smallest branch would have a TC500, hooked via a multidrop line to the central mainframe sites.

It's also worth noting that many of the Burroughs computers of that era used a "made specially for us" logic family (actually Fairchild CTL) with split-rail supply (+4.75 -1.25 IIRC) and most of the faultfinding procedures specified that test equipment's protective ground should be disconnected at the mains plug. I had the misfortune to work for them at the time, and we were given warning notices to display lest we killed ourselves.

MarkMLl
 

Offline mbennett555

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Re: Old Fluke Multimeters
« Reply #731 on: June 29, 2020, 07:08:17 pm »
To drtaylor:  I've been a big fan of the Fluke 8060A since I became aware of it-- 1982, as I recall.  At the time, I was working for Western Area Power Administration, part of the US Department Of Energy; in the Fort Collins, CO office.  (It was my first electrical engineering job.  WAPA owns hundreds of miles of high voltage electrical transmission lines in the western US.)  At first, the WAPA office purchased just 1 Fluke 8060A, and it was for another group located in the same building.  I remember that WAPA paid $400 for it.  (Using an annual inflation rate of 3.5%, I calculate that the price is equivalent to $1480 in 2020.)  Thankfully a colleague in that other group allowed me to borrow the 8060A if it was available, and even take it home from time to time.  I was immediately impressed with it.  As you know, no other handheld DMM at the time came close to its accuracy and its features (including True RMS, of course).

At this time I own 4 Fluke DMMs:  1 Fluke 87V, 1 Fluke 83V, 1 Fluke 189, and 1 Fluke 8060A.  I like all of them.  I purchased the 8060A about 6 years ago from an Ebay seller.  It was in almost-new condition, and it came in its original box, with its original accessories.

Of the Fluke DMMs I own, the Fluke 8060A is, of course, the oldest-design model.  But if I want to measure continuity, it's the one I use.  This shouldn't surprise you, because you explained the reason during a recorded interview, where you talked about the 8060A and its design.  (I found the interview about 3 years ago via the EEVblog, and I listened to the entire interview.)  As you explained, you and the design team decided to use an analog circuit for the continuity function, in order to make its response time very fast.  I agree:  it's very easy for me to hear that the 8060A's response time for its continuity function is clearly faster than the response time of any of my other 3 Fluke DMMs.

I have a question for you, please.  First, here's some info on my Fluke 8060A.  Its serial number is 6849001.  I opened the case and looked inside.  On the main PCB, I saw "8060A-3001 REV M" (machine printed); on another part of the main PCB, I saw "REV K" (the "K" was handwritten).  On a small daughter board, under the EMI cover, I saw some SMD components, including an Analog Devices AD820 op amp.  On just 3 or 4 components, I saw date codes (YYWW, where YY is the year, and WW is the week).  Each date code corresponds to Year= 1996 or Year= 1997.  My 8060A's LCD display is exceptionally clear and has very good contrast; in fact it has better contrast than any of the LCDs on my other Fluke DMMs.

My question is:  what was the last year (approximately) that Fluke manufactured the 8060A?  I know that, according to the interview I listened to, you haven't worked for Fluke for a while.  If you don't have a good guess for the year, do you have a suggestion for how I could find out?  (Over 1 year ago, I called Fluke's 800 number, but no one was able to assist me with the question.)

Thank you.
« Last Edit: June 29, 2020, 10:57:16 pm by mbennett555 »
 

Offline helius

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Re: Old Fluke Multimeters
« Reply #732 on: June 30, 2020, 01:41:03 am »
The last version of the 8060A was CAT I 300V rated, with DC and AC voltage ranges reduced to 300V. It was introduced in mid-1997 with serial 6851xxx. The meter was probably discontinued shortly thereafter (those specs are pretty poorly competitive for 1997), but some new units evidently remained in the retail channel until at least 2000: see this archived sales page from onlinecomponents.com.
 
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Offline bluey

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Re: Old Fluke Multimeters
« Reply #733 on: July 01, 2020, 09:32:57 pm »
for hand-helds I'm a huge fan of the 8060a (the manual is fabulous as is the additional info available thanks to Dave T!), and I also like the 80 series (particularly the 87 - but the 87-1 and 87-2/cat3 versions are easier to fix than the 87-3)

It's a toss-up which one I grab off the bench but I probably grab the 87 more just because I don't mind if I break it.

oh, and both have the same dc volts accuracy of 0.05% (except the +counts are 1 and 2 for the 87/8060)

8060a has superior performance. Basic DCV accuracy of 87-I 87-II and 87-III is 0.1%, based on 1.2 V bandgap voltage reference. 87-V and presumably 87-IV have 2.5V bandgap voltage reference to improve accuracy.

https://www.eevblog.com/forum/testgear/i-need-to-know-the-history-of-fluke-87-(-1998-2010-)/msg3089490/#msg3089490

PS only just discoverer this thread. Fascinating jewels of history, esp links to history of DVM rooted in atomic bomb research; Fluke 8300 which i guess is where the model number 83 comes from; and drtaylors designer insights; intersil IP theft. Fascinating that korea and germany have cloned the Fluke DMM in the early 80s as Hung Chang and Voltcraft.
« Last Edit: July 01, 2020, 09:47:41 pm by bluey »
 

Offline bluey

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Re: Old Fluke Multimeters
« Reply #734 on: July 03, 2020, 11:24:28 pm »
The 8060A manuals from Fluke manuals page start 1997.

This one from internet archive has copyright 1982, so should properly describe the early models prior to revision. I presume revision would be for CAT ratings similar to 87-II update.

https://archive.org/details/FLUKE_8060A_Instruction
 

Offline bluey

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Re: Old Fluke Multimeters
« Reply #735 on: July 03, 2020, 11:45:50 pm »
Some questions for DRT if he is still here:

1. The 8060A release article you wrote describes a buried Zener voltage reference. The manual above says it is a bandgap voltage reference. I thought the two are slightly different. Did the design change somewhere?

2. ELectronics Australia 1990 article describes the general theory and operation of a DMM. (A great read.)
https://www.eevblog.com/forum/testgear/i-need-to-know-the-history-of-fluke-87-(-1998-2010-)/msg3033264/#msg3033264
The generic DMM resistance function is explained as measuring the voltage using a constant current generator to derive resistance. The 8060A and 87 use a ratio compared to a reference resistor, rather than a constant current generator. I presume this simplifies the design wiithout affecting accuracy. 87 has fuse test plus 1000ohms as a sanity check, but the ratio method seens to make this an insane sanity check because it really only checks the reference resistor and voltmeter could be anywhere and fake correct resistance. Interested in your perspective.
 


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