Products > Test Equipment
Old Fluke Multimeters
Napalm2002:
I have one near mint 8060a one very good condition both in excellent working condition and an ibm 8060a with case and probes for 61$ love the old meters. It has an almost expert kind offeel to it because u can't be and idiot and u kind of h and to put the range switches in the right spot or else......
scopeman:
--- Quote from: drtaylor on July 03, 2014, 08:58:47 pm ---Sam,
I doubt that your problem is the divider. I would suspect the pushbutton switch assembly with the symptoms as you describe. Sometimes the little spring contacts in the switch get mangled.
With the 8060 off, check each switch to make sure the poles are connecting and disconnecting. The ground side of the divider has to go through several poles on several switches. Any pole not working would prevent the divider from dividing.
It's fairly easy to test if the divider is working. Just place 2V on the meter inputs and then monitor the voltage at the 100k resistor at the input to the MAC chip. Also, if you pop out both the Volts and ohms keys, then you can use another DMM to measure the resistors in the divider (8060 off).
Also a small possibility is that the silver zebra that connects the main board to the SM4 Micro just needs to be cleaned and/or repositioned. If this were the case, it would still divide in the analog world, but the micro may not know what range and function it is in.
Does it work in ohms mode? That would be a clue.
The divider was a custom part from Caddock to my specifications. I don't believe it was used ever again in newer meters. So unless Fluke has repair stock, that might be difficult to obtain except from a donor 8060. Hopefully your divider is fine.
I don't have an 8060 schematic where I'm writing this. If you want more specific instructions on trouble shooting this unit, let me know. Good luck.
If you have the User Guide, it tells you how to perform a digital switch check that will test the Micro's ability to figure out the range and function.
--- End quote ---
Hello Dr. Taylor,
Well this is embarrassing for an old sparky like me to admit, but once I spent some time with it the problem was staring me right in the face. The real problem was the switches were in the wrong position! I had it in the high Z mode (all of the gray switches out) instead of the middle gray one in and the others out! A simple case of operator head space. I guess in my mind I did not think of that V/dB switch mattered when measuring DC! Sometime you just have to read the manual even if it is a PDF!
With that bit of head slapping out of the way I proceeded to check the unit on my voltage calibrator and it was (of course) dead on. Mine is serial number 4310057. After checking the cal I took it apart and cleaned the case with some water and a little dish soap gently with a Mr. Clean Magic Eraser (works wonders on surplus test gear)
Now the unit looks good as new ! Truly a great design. I do need to run the unit through its paces on AC but I don't have access to my AC test gear tonight, Maybe next week!
I do thank you very much for the troubleshooting hints as they will help someone else along the way for sure.
Sorry to have put you through that for such a simple solution!
All the best,
saturation:
Dr Taylor, glad you posted this thread for posterity, in many ways the modern hand held DMM as a device was "created" by Fluke, and moreso, IMHO, by you and your team. I missed this thread and the AmpHour interview, but there are always the archives.
I could never afford a Fluke DMM until my post grad years, but worked summers enough to buy a clone. For decades I wondered about how they copied the design and function so well, until your story about Intersil. It seems it was more than good reverse engineering ^-^ Many HH DMMs, particularly low cost ones from Taiwan from the early 1980s used the ICL7106 and at times the 7107, for benchmeters.
drtaylor:
Saturation- Thanks for the kind words. I really appreciate it. You can listen to the Amphour interview anytime at http://www.theamphour.com/180-an-interview-with-dave-taylor-multi-talented-meter-maker/.
For those who have been eagerly awaiting me putting some of my 8060s up for sale, I ran into a snag. Even though I used Tantalums in more positions than the production 8060s, I still had one 100uF aluminum cap that spewed. So the IBM labeled 8060 does not work accurately in the Megohms range. So next I will replace the one remaining alum cap and do a thorough IPA clean. All functions seem to be working other than high range ohms. A few segments on the LCD are light, which I'm sure will be fixed with a zebra strip cleaning. This one has not been turned on in 30 years. I'm amazed it worked as well as it did. Should be fully restorable.
After working on electronics all day, I sometimes just don't get up the gumption to work on them after I arrive home. Lazy, I know. Plus I'll have to go out and buy some 99% IPA... So, sorry I'm so slow.
Next I will test all my 8060s to see which ones need work. All have original caps, so I probably need to do some removals, cleaning, and new part installations.
Once fully restored, I'll post them on the Forum and offer the buyer a choice if he wants them signed, internally or externally or in just the User Guide. I have enough User Guides to cover all the 8060s I plan on selling, which is three right at the moment. 1 IBM, and 2 Fluke versions. Watch this topic over the next few weeks, and I'll announce it here right before posting them in the sales area. These are first hard model run units with the higher bandwidth Motorola TRMS circuit, and the higher AC input voltage range. So they will be the oldest 8060s available, but should perform as well as any 8060 ever made.
saturation:
My pleasure, listened to it yesterday. When you read Fluke's own history of the HH DMM:
http://support.fluke.com/find-sales/download/asset/2386856_a_w.pdf
You came in a key moment in history and help add functions that became a defacto standard in DMMs.
Here are some clones that used the 7106 that was very popular at the time. The manufacturers even copied the switch layout suggests how popular the 8020a and subsequent models were.
--- Quote from: drtaylor on July 15, 2014, 11:22:20 pm ---Saturation- Thanks for the kind words. I really appreciate it. You can listen to the Amphour interview anytime at http://www.theamphour.com/180-an-interview-with-dave-taylor-multi-talented-meter-maker/.
--- End quote ---
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