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I am trying to measure the resistances of the power tranny I took out of my 845 to use in psudII. When I try measuring the secondaries with high range the display flashes at me (fluke DVM) and won't give me a reading. The prinaries read 2 ohms
When I use the low range (also the continuity checker) I still get 2 ohms on the primaries and I get a continuity tone, but on the secondaries I get about 75 ohms but no continuity tone. I know this is a working tranny because it was in my 845 and working fine until I took it out just last night. What am I seeing here?
Vince
Follow Ups:
I learned something new tonight!
VinnieThe Fluke will not sound when
the impedance is above 50 ohms.
I have a Fluke LCR meter and
that's it's story.
No problem here.
Welcome to a crappy Fluke meter. The tranny is fine. We used to throw these things away by the numbers. Better and cheaper to get a new than cal the old one.
But I hardly think a $200 fluke deserves the label of crappy. I did a lot of research before I bought it and it got nothing but high marks. It has also worked just fine for these last eight years, including surviving some stupid moves on my part. I think there is something else going on. I did notice that when I measured between the center tap and each side it worked ok. I might have to try putting a new battery in, it's been a couple of years.
It's a "fluke" due to autoranging when measuring some inductors. As it switches to the lower range, the current goes up, and so does the voltage drop (momentarily), causing it to switch back to the higher range. So just set the range manually and all will settle out. And use insulated clips - DON'T be touching the wires when you OPEN the circuit. Don't ask how I know this...
I love my flukes, but I've had this glitch. Of course, I know the workaround; go on manual and get to the range that gives you the reading. Thanks for elucidating the mechanism.No, boyze, your Flukes are not P O S. I have three, two 27s (the pride of my bench), and a 73 for my road axe. On any measurement, these three (one calibrated a year ago, one three, one no data) agree to the third significant figure.
The 27 is O-ring sealed, built for mine safety, and all that good stuff. Doubles as a hammer. I'd think it would be the best one to have bouncing around in the car. I still have mine (somewhere) and it has to be over 20 years old.Don't be in a hurry to upgrade. I have the new 189 and it has some nice features but it is big and....well....I liked my old model 87 more....what can I say. They also changed the amp probes....for the worse.....and the lifetime warranty looks to have gone away as well.
and comes in that bright yellow condom, so I can find it in the pile with my specs off.All the Flukes have sort of a dark display, don't they? You got to have real good light on them to read them easily.
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I agree with russ57 but I think it's a service feature built in. The 87, 787 and 789 are standards in my trade. Rough tough and built to take a licking like in the coal fired powerhouse I'm working in now.
The inductance is working against you. This is a situation where an analog meter will do a better job than the Fluke. FWIW, my Fluke does exactly the same thing, so I've learned to work around it.
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