Products > Test Equipment
Fluke 8000A Multimeter Reading 1/2 of Actual Values
bdunham7:
--- Quote from: TMA-1 on January 18, 2024, 03:37:44 am ---How about,.. replace the 5000MF 15WVDC capacitor (about the size of a tanker rail car), with a 4700uF 25VDC capacitor that I can salvage, and add a 7805? Should I experiment with that?
--- End quote ---
If the existing capacitor is signficantly degraded replacing it might help (and that part you are suggesting will be fine) but the voltage will become normal at most, no headroom for an LM7805. You didn't mention what other meter you have, but assuming it's an ordinary digital DMM, try measuring the 5V rail using your AC range and see what you get for ripple. Actually it would help to know the make/model of the meter as well.
TMA-1:
Oh, right. I got carried away there, maaaad with power. I suppose I could use an up-converting buck converter, and then regulate it back down to 5V, but that's just too icky.
I'll do what you suggest momentarily.
I have a Vichy V97, which is not the best. In fact the capacitance test is garbage, I just found out during this little escapade. But the more expensive Mastech MAS345P CLONE that I have has a broken continuity check (NOT the buzzer element), so I tend to toggle a lot.
The Mastech clone let me down once though also. It outright read the wrong voltage on one particular circuit, a conclusion eventually backed up by 3 other meters. Scared the marrow out of me.
Hence I'd like a third opinion handy, in the form of this FLUKE, flawed though it may be.
They say never put to sea with two compasses. If you can't take three, only take one. :D
[Edit] It works! I'm getting 5.3VDC, and 0.06VAC ripple. And my power supply once again reads 13.67VDC. Yay! I will of course check the other functions and ranges, but have no reason to suspect there will be other problems.
Thank-you bdunham7, and AVGresponding, for the excellent helmsmanship. Your karma accounts runneth over.
tautech:
Eeeek, a TANT ! :scared:
Just because it's lollipop red don't think it won't throw a curveball somewhere down the track.
Get that sucker outta there for a new and higher voltage rated one.
Martian Tech:
I'll bet this thread would be happier in the https://www.eevblog.com/forum/repair/ forum...
AVGresponding:
--- Quote from: Martian Tech on January 19, 2024, 04:08:22 am ---I'll bet this thread would be happier in the https://www.eevblog.com/forum/repair/ forum...
--- End quote ---
There's a lot of crossover. It's fine where it is afaic, and I wouldn't have seen it there, so wouldn't have mentioned the 5V rail mod. Ultimately it's up to the OP and the mods (who are not heavy handed on this).
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