Test Equipment Anonymous

Zenith wrote: ↑Mon May 19, 2025 10:25 pm

tggzzz wrote: ↑Mon May 19, 2025 9:25 pm I've little appetite for polishing a boring 3.5 digit turd - and improving this is definitely whack-a-mole territory.

A working 3.5 digit bench DMM is OK. It doesn't run out of battery. If it doesn't work, it's in dustbin territory. However the processor is the same as used in better models, so if you are inclined to chuck it, remember me. I have an 8800A which I think has a shot controller IC.

It has a strange IC, part of a controller rather than an integrated controller like the ICL7126 family. FFI, see the manual.

Can't hold that against Fluke; clearly they were pushing the available technology.

tggzzz wrote: ↑Tue May 20, 2025 7:50 am Don't deliberately confuse that case with the inexperienced and impecunious amateur use case, where the tradeoffs can be very different.

Certainly not, I was one but as experience grew I ditched the old stuff in favor of something I could trust to still operate when required.
Still an amateur but no longer so impecunious I can buy what I need or better than I need for continuing personal lifelong development.

TEA is no longer of interest, outgrown that......

Zenith wrote: ↑Mon May 19, 2025 10:40 pm

tautech wrote: ↑Mon May 19, 2025 10:20 pm So are the prized by some CRO's of yesteryear yet their addition cost of ownership now is keeping them going.....

They have a savage grandeur which many find fascinating. Valve scopes are probably now a bit too savage for most.

Especially savage on the back

There's only one hollow state scope I would consider, because it was pushing technology in all sorts of ways and the basic readability/usability wouldn't be matched for another quarter of a century!

I refer, of course, to explicitly highlighting where the measurements of V_low, V_high, and t_rise are being made.

Introduced in 1962, so no ICs could be used, and computers were out of the question!

tautech wrote: ↑Mon May 19, 2025 10:52 pm

MED6753 wrote: ↑Mon May 19, 2025 10:43 pm

tautech wrote: ↑Mon May 19, 2025 10:02 pm Based on this thread, shouldn't we declare Fluke products as a crap shoot.....
Gimme a mo to grab my hat and coat....

I have several Flukes here. 8600A, 8010A, 8050A, 8800A and they all perform well. In addition to hand helded 8021B, 8060A, and 87. The 8000A is the only dud.

Yup, all brands have their dog models .....

Yup, and that's why it is worth commenting on this unexpected surprise.

When HP introduced a minicomputer that didn't meet its specs, Packard sent a stinging memo to the project director, Paul Ely. "Please do not introduce products that do not meet their specification". Ely framed the memo, hung it on his wall, and went on to have a good career at HP

The story was propagated as a "Bill and Dave" anecdote used to propagate HPWay values whenever new sites were being set up.

tggzzz wrote: ↑Tue May 20, 2025 7:53 am

Zenith wrote: ↑Mon May 19, 2025 10:25 pm

tggzzz wrote: ↑Mon May 19, 2025 9:25 pm I've little appetite for polishing a boring 3.5 digit turd - and improving this is definitely whack-a-mole territory.

A working 3.5 digit bench DMM is OK. It doesn't run out of battery. If it doesn't work, it's in dustbin territory. However the processor is the same as used in better models, so if you are inclined to chuck it, remember me. I have an 8800A which I think has a shot controller IC.

It has a strange IC, part of a controller rather than an integrated controller like the ICL7126 family. FFI, see the manual.

Can't hold that against Fluke; clearly they were pushing the available technology.

Those 40 pin ICs were were used for control and display. They used them in several designs. There were a couple of versions and on the 8800A you have to add or remove a jumper, depending on which one is used. They are known to fail and are unobtainable as NOS.

I am sure the control/display IC has failed in my 8800A. I am wondering whether it can be replaced with board based on a Raspberry Pi Pico or Arduino. However, putting in a part from an 8000A is the easier option. There may be other parts worth retrieving from the 8000A, such as the voltage reference, stabistors and op amps.

So while the 8000A may be the black sheep of the Fluke family, they are not completely worthless. Furthermore, they are not very expensive or big and heavy, unlike vintage SAs. So taking a long view, the £5 you spent on the 8000A may not have been entirely wasted, the same as the £5 I spent on my declared non working 8800A. I don't think it's sensible to pay a lot for any of this old junk.

The Intersil 7106 & Co was used in a lot of DMMs. I've just given away a DMM with a 40 pin one in. More often they are mounted directly on the board and covered with a blob of something. I heard it was some sort of collaboration between Fluke and Intersil. Anyway, out of it came the 7106 which Intersil sold, to Fluke's annoyance, and there was a law suite.

Zenith wrote: ↑Tue May 20, 2025 8:43 am

tggzzz wrote: ↑Tue May 20, 2025 7:53 am

Zenith wrote: ↑Mon May 19, 2025 10:25 pm
A working 3.5 digit bench DMM is OK. It doesn't run out of battery. If it doesn't work, it's in dustbin territory. However the processor is the same as used in better models, so if you are inclined to chuck it, remember me. I have an 8800A which I think has a shot controller IC.

It has a strange IC, part of a controller rather than an integrated controller like the ICL7126 family. FFI, see the manual.

Can't hold that against Fluke; clearly they were pushing the available technology.

Those 40 pin ICs were were used for control and display. They used them in several designs. There were a couple of versions and on the 8800A you have to add or remove a jumper, depending on which one is used. They are known to fail and are unobtainable as NOS.

The 8000 has "U3 analog" "U4 digital" and a "U5 7447 BCD->7 segment decoder/driver". U3 and U4 are clearly "specials".

I designed an ICL7126 into equipment, back in the late 70s

tggzzz wrote: ↑Tue May 20, 2025 8:50 am

Zenith wrote: ↑Tue May 20, 2025 8:43 am

tggzzz wrote: ↑Tue May 20, 2025 7:53 am

It has a strange IC, part of a controller rather than an integrated controller like the ICL7126 family. FFI, see the manual.

Can't hold that against Fluke; clearly they were pushing the available technology.

Those 40 pin ICs were were used for control and display. They used them in several designs. There were a couple of versions and on the 8800A you have to add or remove a jumper, depending on which one is used. They are known to fail and are unobtainable as NOS.

The 8000 has "U3 analog" "U4 digital" and a "U5 7447 BCD->7 segment decoder/driver". U3 and U4 are clearly "specials".

I designed an ICL7126 into equipment, back in the late 70s

I was wrong. it doesn't use that 40 pin controller.

Researching it further on the WWW, the 8000A seems to be a particularly crappy model.

MED6753 wrote: ↑Mon May 19, 2025 9:52 pm

25 CPS wrote: ↑Mon May 19, 2025 8:21 pm

tggzzz wrote: ↑Mon May 19, 2025 7:30 pm Look more closely, especially at the other side of the connector (with Fluke blue shroud reinstalled) and see there is a shroud made of - wait for it - perforated card?! Involuntary shudder, as I remember Bulgin connectors.

Bulgin plugs. Memories of Quad ESL 57 speakers there.

Anyways, the Fluke 8000A multimeter is a disappointment. This is not the sort of product you'd expect to see the Fluke name on. Micronta or some other Radio Shack branding, sure, but not fluke. I guess every company releases a basketcase of junk to the market at one time or another. I have two Fluke 8000A. One works but the other just displays nonsensical values. I pulled the working one and put it on the shelf once I got my second Agilent 34401A. I have a ton of projects that I inch along on at a glacial pace. The Fluke 8000s aren't on the bottom of the list - they aren't on the list at all.

In the 1970's I worked Final System Test of IBM System370/3158 and we were required by engineering to use the 8000A to set the power supply voltages. The main voltages were +1.250V and -3.00V. No matter how much you twiddled the power supplies they would either sit at +1.252V or +1.249V. Never could figure out if it was the DMM or the power supplies. I suspect it was the Fluke based upon what I've seen all these years later fixing it's design flaws.

I'd suspect the 8000A too but it would be interesting to know for sure whether it was the computer power supplies or the meter, or possibly both moving around. Did the test lab have any other DMMs besides the Fluke 8000As that you could sanity test the same power supply against?

tggzzz wrote: ↑Tue May 20, 2025 7:44 am My other Flukes are stunningly good, much more so than I would have believed.

When I get one I expect to have replace an electrolytic and/or clean a switch. If that is necessary, thereafter they are still spot on.

Zenith wrote: ↑Tue May 20, 2025 10:01 am Researching it further on the WWW, the 8000A seems to be a particularly crappy model.

It's hard to believe that the 8000A is from the same company as the 8300A, or the 8125A, or indeed the 8840A

AVGresponding wrote: ↑Tue May 20, 2025 5:16 pm

tggzzz wrote: ↑Tue May 20, 2025 7:44 am My other Flukes are stunningly good, much more so than I would have believed.

When I get one I expect to have replace an electrolytic and/or clean a switch. If that is necessary, thereafter they are still spot on.

Zenith wrote: ↑Tue May 20, 2025 10:01 am Researching it further on the WWW, the 8000A seems to be a particularly crappy model.

It's hard to believe that the 8000A is from the same company as the 8300A, or the 8125A, or indeed the 8840A

Or the earlier voltmeter with a digital readout, the 893A. Still my only meter that will read 1kV while taking zero current. None of the normal 0.1mA at 1kV crap

Perhaps they were different companies, with rebadged low-end scopes, or equivalent to the Tek/Telequipment divide.

tggzzz wrote: ↑Tue May 20, 2025 5:23 pm Or the earlier voltmeter with a digital readout, the 893A. Still my only meter that will read 1kV while taking zero current. None of the normal 0.1mA at 1kV crap

Perhaps they were different companies, with rebadged low-end scopes, or equivalent to the Tek/Telequipment divide.

Is that a null meter?

25 CPS wrote: ↑Tue May 20, 2025 4:38 pm

MED6753 wrote: ↑Mon May 19, 2025 9:52 pm

25 CPS wrote: ↑Mon May 19, 2025 8:21 pm

Bulgin plugs. Memories of Quad ESL 57 speakers there.

Anyways, the Fluke 8000A multimeter is a disappointment. This is not the sort of product you'd expect to see the Fluke name on. Micronta or some other Radio Shack branding, sure, but not fluke. I guess every company releases a basketcase of junk to the market at one time or another. I have two Fluke 8000A. One works but the other just displays nonsensical values. I pulled the working one and put it on the shelf once I got my second Agilent 34401A. I have a ton of projects that I inch along on at a glacial pace. The Fluke 8000s aren't on the bottom of the list - they aren't on the list at all.

In the 1970's I worked Final System Test of IBM System370/3158 and we were required by engineering to use the 8000A to set the power supply voltages. The main voltages were +1.250V and -3.00V. No matter how much you twiddled the power supplies they would either sit at +1.252V or +1.249V. Never could figure out if it was the DMM or the power supplies. I suspect it was the Fluke based upon what I've seen all these years later fixing it's design flaws.

I'd suspect the 8000A too but it would be interesting to know for sure whether it was the computer power supplies or the meter, or possibly both moving around. Did the test lab have any other DMMs besides the Fluke 8000As that you could sanity test the same power supply against?

It wasn't a lab. This was a production area where we tested and shipped the mainframes. The 8000A was the only DMM available to us for use in the production area.

To us techs on the production area these 8000A's were "the Bomb". The "bees knees". Greatest thing since sliced bread. We had never seen or used a small and compact DMM with LED's. So all these many years later I wanted one and then found out what a piece of crap it was. This was from the same engineering group which had us use exclusively hp 180A scopes which weren't bad but we were used to Tek scopes and we hated them.

When the follow on mainframe 303X came out the 8000A's were kicked to the curb because the mainframe power supplies were micro code driven and their voltages could be set via the main CRT console. And the 180A's were also kicked to the curb and got brand new Tek 475A/DM44.

MED6753 wrote: ↑Tue May 20, 2025 6:16 pm To us techs on the production area these 8000A's were "the Bomb". The "bees knees". Greatest thing since sliced bread. We had never seen or used a small and compact DMM with LED's. So all these many years later I wanted one and then found out what a piece of crap it was. This was from the same engineering group which had us use exclusively hp 180A scopes which weren't bad but we were used to Tek scopes and we hated them.

When the follow on mainframe 303X came out the 8000A's were kicked to the curb because the mainframe power supplies were micro code driven and their voltages could be set via the main CRT console. And the 180A's were also kicked to the curb and got brand new Tek 475A/DM44.

Tektronix 475 with DM44 is a nice combination. That's still my go-to when possible at work. Unfortunately, that also does speak to the test equipment situation at work though given it is 2025 after all.

AVGresponding wrote: ↑Tue May 20, 2025 5:26 pm

tggzzz wrote: ↑Tue May 20, 2025 5:23 pm Or the earlier voltmeter with a digital readout, the 893A. Still my only meter that will read 1kV while taking zero current. None of the normal 0.1mA at 1kV crap

Perhaps they were different companies, with rebadged low-end scopes, or equivalent to the Tek/Telequipment divide.

Is that a null meter?

Yup. Hence my using the obfuscatory "digital readout", i.e. the dials of a KVD.

25 CPS wrote: ↑Tue May 20, 2025 6:30 pm Tektronix 475 with DM44 is a nice combination. That's still my go-to when possible at work. Unfortunately, that also does speak to the test equipment situation at work though given it is 2025 after all.

Around 1980 I had a colleague who'd worked in production in a burglar alarm factory a few years before. They weren't assigned an oscilloscope, they had to grab one from the pool after they clocked in. The early birds got a Solatron CD1400, the last in got the ancient Heathkit.

One of the customers specified that no Radiospares (now RS components) parts were to be used in products they bought. There was a Radiospares branded relay they used. Standing orders were to scratch off the Radiospares lettering with a finger nail.

Fine instruments that they are, I'd have thought Tek 475s were getting a bit long in the tooth for daily use. The one I bought in 2009, and used fairly regularly for some years, has died twice. Once because of a dead reservoir cap and once because a transistor suddenly croaked.

Cubdriver wrote: ↑Tue May 20, 2025 1:50 am

Got my own CAT scan the other day and been called back for another.....
This getting older is a real bitch.....