Fluke 77 behavior

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IBMJunkman
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Fluke 77 behavior

Post by IBMJunkman » Thu Mar 22, 2018 9:57 am

I have had my trusty Fluke 77 for decades. I am listing some JBL recone kits on eBay and wanted to include a picture of the DC ohms readings of the voice coils.

I saw the readings varying by .5 ohms up and down as I watched. I replaced the battery. No joy. With leads shorted reading varied from 0 to .2 ohms. Testing was done on a wood table with no AC source within 8 feet.

Should I give up the ghost on this unit? Is this normal? Is there anything I can do?

A new 117 costs $175 with lead set on Amazon. It does measure frequency. :smile:

Robert Reed
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Re: Fluke 77 behavior

Post by Robert Reed » Thu Mar 22, 2018 4:47 pm

Make sure the lead jacks on the meter are perfectly clean, then insert a short banana/banana jumper (one that is known good) into the meter jacks and note readings. My Fluke never gives consistent readings under the situation you described. The culprit has always been poor contact resistance of the probes (the jaw type are the worst). Occasionally a cleaning of the meter jacks is necessary.

IBMJunkman
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Re: Fluke 77 behavior

Post by IBMJunkman » Thu Mar 22, 2018 6:03 pm

Well, twisted the plugin leads in the sockets on the meter a few times and in the probes. Shorting the leads get a 0.1 initially then it drops to 0.0 and stays. Thanks.

I really wanted the 117. :smile:

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CeaSaR
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Re: Fluke 77 behavior

Post by CeaSaR » Thu Mar 22, 2018 8:45 pm

Darn, I was going to suggest that, but Robert beat me to it. :)

Well, you can always disregard that advice and buy the 117 anyway. You can never have too many meters. :D
Hey, what do I know?

IBMJunkman
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Re: Fluke 77 behavior

Post by IBMJunkman » Mon Mar 26, 2018 9:16 pm

Well, I gave into my geek and bought the 117. Had it delivered to my Vegas house. I already had a Fluke there but did not know what is was when I ordered the 117. Found it was a 81438.

With leads shorted the 117 measures a steady 0.1 ohms. Using the same leads the 81438 starts at 0.2 but then dropped to a steady 0.1

A little research shows the 81438 was apparently a Sears model Fluke 111.

Fluke 77 in CA, 117 in NV. Guess I need to buy another house to house the 81438. :grin:

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Lenp
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Re: Fluke 77 behavior

Post by Lenp » Wed Apr 11, 2018 8:10 am

If you used a venerable Simpson 360 or Triplett 630......
That would not have been a problem :???:
Len

“To invent, you need a good imagination and a big pile of junk.” (T. Edison)
"I must be on the way to success since I already have the junk". (Me)

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