FLUKE 332B/AF in the slaughterhouse

[BU508A]

But I still have the plan to "pimp" it on the chopper (reduce short term drift) and reference (reduced long term drift).

And how exactly do you want to do this? Just curious .... :-)

[pelule]

How to do?
First check, if it makes sense, analyse the options, the eforts in time & cost, than kill or start the project.
That  I did.
Tool offers DC voltage up to 1111V, DC current up to 111 mA (for burden voltage up to 500V).
Design is quite good from the principle, the used precision resistors, the power supply, the pre-regulator solution, the shielding. The Plug-In card design allows a partly "pimping" with acceptable efforts (you do not risk the total system).
Just the old style chopper amp and the reference prevent a much better level of precision.
A good example you may find at FM, as mentioned by Dr.Frank already.
http://www.friedrich-messtechnik.de/index.php/bauanleitungen/87-fluke335-332
My Project Plan
Step 1: get it to full function / repair - Done
Step 2: measure actual short term drift - Done
  ~12 pmm, thus the chopper replacement is a potential option
Step 3: measure the long term drift - still running
  ~40 ppm/y so far according to 3458A, still inside the spec (6 ppm/month), but a potential option to replace
  thinking in the LTZ1000A as I have one spare, but LM399H may also an option.
Sounds serious, isn't it?

[BU508A]

Yes it does.  What I wanted to know was the technical part, e.g. replacing the reference and or the amplifiers.
I saw that link from Dr. Frank but I didn't check it out yet. I was busy in finding out, what these connectors are.

I think I will not do that to my Fluke. Even if I would, I can't measure it. I do not have a 3458A or similiar.

But, regarding the connectors: I think I hunted them down. They are probably ELCO Varicon Series 5208 from AVX.
I found a datasheet here, which is looking quite promising: http://www.avx.com/prodinfo_productdetail.asp?I=622&K=search&C=&word=Varicon

Now to find a distributor which have them and is willing to sell stuff to private people.

[pelule]

Arrow Europe is one of their distributors.
The gold stripe contacts seem to be the right one, but I could not find the plugs (single row).
Seems they are "NO LONGER MANUFACTURED/NO REPLACEMENT".
Had the idea to by another 3330B for parts only. One is offered in the US, waiting for response regarding int. shipping.

[guido]

A good example you may find at FM, as mentioned by Dr.Frank already.
http://www.friedrich-messtechnik.de/index.php/bauanleitungen/87-fluke335-332

I've done just that. See here: https://www.eevblog.com/forum/testgear/fluke-332a-adjustmentverification/msg685631/#msg685631

ps, i've replied. You're lucky, i have one spare pcb left.

[casinada]

I got the same unit waiting to be repaired under my desk (3330B) but haven't had the time to get to do it.   

[pelule]

I've done just that. See here: https://www.eevblog.com/forum/testgear/fluke-332a-adjustmentverification/msg685631/#msg685631

Looking nice and professional. What's your experiance of the improvement?
Did you do any change on FM's circuit or just made a nice PCB out of it?
Willing to sare the schematic and PCB data?

Analog Devices a while ago presented a new generation of zero-drift amplifieres. They shall be able to operate at higher supply voltage and promoted as lower noise. So far just available as dual Version, so could replace LT1150 and LT1001, would not need the 7xL05 anymore. Only negative point, they are not available as DIP.

[BU508A]

Here are some additional information regarding this ELCO connectors:

connectors soldered on the cards:
Fluke part number: 187724
NSN number: 5935009160845
AVX part number: 02-016-013-5-200

connectors soldered on the motherboard:
Fluke part number: 187732
NSN number: 5935-00-628-8750
AVX part number: 00-5009-016-153-001

I found these parts available at www.netsemi.com but you have to request a quote.

It seems, that these parts in Europe aren't available (anymore, if they were ever).

[pelule]

I found these parts available at www.netsemi.com but you have to request a quote.

This page is crap. I did my standard test and asked for stock of "HumptyDumpty)
result: HUMPTYDUMPTY is in stock! Enter a quantity below to check pricing.

I am waiting for feedback from AVX/Kyocera - if that part is still manufactored & offered (and if, where to buy) or is obsolet (and if, still some NOS existing)

[pelule]

I got a feedback from the AVX European sales manager.
This part is obsolet for some years now. There is no old stock available at AVX.
Thus he does not expect, there is some available at the distributors (Arrow, Mouser, Farnell).
He recommend to check up for NOS in WWW.

[BU508A]

This page is crap. I did my standard test and asked for stock of "HumptyDumpty)
result: HUMPTYDUMPTY is in stock! Enter a quantity below to check pricing.

I am waiting for feedback from AVX/Kyocera - if that part is still manufactored & offered (and if, where to buy) or is obsolet (and if, still some NOS existing)

Seems, that I'm way to naive to this world. :-(

I looked also for NOS and surplus sources, but I did not manage to find a real good source. The parts I found were quite expensive so I'm really curious about the response from netsemi, if there will be one.

Btw, I found this 3330B on ebay as well. Probably we can share the guts, if the seller is willing to deliver to Germany.

Will keep you updated.

[guido]

I've build this thing because the readings on my DMMs where not stable. After it was done nothing changed much. Turned out that my DMMs where the problem   Since then i got another HP3456A which is stable on the 335D. I did not put the old chopper back to compare. The changes to the original schematic are a single non polair cap on the output (the green MUSE cap) and i've added a multiturn pot + resistor for R10. The potmeter lines up with a potmeter on the original pcb, so you can access it easily. Doesn't do much though 

I still need to have a go at the faulty 3456A and a Prema 5000. But the last one now also lost calibration (loose connection with the crappy IC socket on the RAM IC). And the 335D nullmeter still needs fixing. Winter is around the corner and i've got parts now.

PS. I'm now out of PCBs with connectors of Dr. Frank's 332. Last one just went on the mail.

[BU508A]

Got the quotes for these connectors. They are a bit pricy ....

connectors soldered on the cards:
Fluke part number: 187724
NSN number: 5935-00-916-0845
AVX part number: 02-016-013-5-200
Qty: 3
Price per unit: 66.67$
Total: 200$

connectors soldered on the motherboard:
Fluke part number: 187732
NSN number: 5935-00-628-8750
AVX part number: 00-5009-016-153-001
Qty: 10
Price per unit: 15.99$
Total: 159.90$

Thanks, but no thanks.

[pelule]

When I was working for a Japaneese semiconductor supplier, we called such a "Japaneese No".
Means, if you do not wan't to say NO, you lift the price to such a height, the potential buyer is not interested anymore.

[Inverted18650]

I know this is very old but if there is a 332B/AF "capacitor switch board" available, I would love to buy one.

[Vgkid]

Why not just replace the caps , unless the board is missing.

[Inverted18650]

Why not just replace the caps , unless the board is missing.

Its missing. Damn shame too, because the unit cleaned up very nicely and seems to really want to be the right thing.

[branadic]

Kind of old thread, but info about this Klixon oven can be found in US4084437 and US3414705A. There are two ovens available on ebay.

-branadic-