Author Topic: Fluke 341A DC voltage calibrator  (Read 9462 times)

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Offline feedback.loopTopic starter

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Fluke 341A DC voltage calibrator
« on: November 26, 2015, 11:24:22 pm »
Check out this repair video. Nice vintage piece of precision gear from 1970s. Not a metrology lab grade, of course, but still very cool 6 digits 0.005%.  A few capacitors failed, but otherwise still in spec.


« Last Edit: May 04, 2022, 04:12:37 pm by feedback.loop »
 
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Online Vgkid

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Re: Fluke 341A DC voltage calibrator
« Reply #1 on: November 27, 2015, 05:07:08 am »
Good job on the repair, amazing that some measurements are almost still within the recently calibrated specs.
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Offline feedback.loopTopic starter

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Re: Fluke 341A DC voltage calibrator
« Reply #2 on: November 29, 2015, 06:35:21 pm »
By the way, I wonder what do the voltage reference gurus on this forum think about the SZA263 used in this calibrator?
 

Offline HighVoltage

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Re: Fluke 341A DC voltage calibrator
« Reply #3 on: November 29, 2015, 08:23:17 pm »
Not a metrology lab grade, of course, but still very cool 6 digits 0.005%.
Thanks for another great video.

Well, it might not be a metrology grade equipment today, but I think in the 70's it was for sure metrology grade.
Especially since most voltmeters were analog in those days.


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Offline splin

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Re: Fluke 341A DC voltage calibrator
« Reply #4 on: November 29, 2015, 10:25:53 pm »
At 11:30 the 34401A is shown measuring 30uV AC of noise - but the 34401A becomes very inaccurate below 1mV and wildly so below about 100uV AC according to this:

http://www.gellerlabs.com/34401a%20ac%20zero.htm

It looks like the Tektronix scope has a problem calculating RMS voltages at low levels - at 12:27  after reducing the b/w to 20MHz it shows the peak-peak value to be mostly similiar to (or below) the RMS value which is unlikely (to impossible). Not that it matters at those levels.
 

Offline dacman

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Re: Fluke 341A DC voltage calibrator
« Reply #5 on: November 30, 2015, 03:13:24 am »
30D series Sprague capacitors have been made since the 1960's (at least) and still are being made.  That 5uF 25V cap is a TE1202 and is available at several parts places (Newark, Allied Electronics, Mouser, Amazon.)

Those Kelvin Clips for the LCR meter look fairly decent.  Is the blade connector custom or would it fit a DE-5000?
 

Offline feedback.loopTopic starter

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Re: Fluke 341A DC voltage calibrator
« Reply #6 on: November 30, 2015, 06:42:09 pm »
30D series Sprague capacitors have been made since the 1960's (at least) and still are being made.  That 5uF 25V cap is a TE1202 and is available at several parts places (Newark, Allied Electronics, Mouser, Amazon.)

Those Kelvin Clips for the LCR meter look fairly decent.  Is the blade connector custom or would it fit a DE-5000?

Regarding 5uF caps. The exact capacitance is not critical there, so 6.8uF should do just fine.

Regarding the LCR meter. I really don't know much about DE-5000. The meter I have is Tonghui TH2822C. Here is a teardown:
https://www.eevblog.com/forum/testgear/tonghui-lcr-meter-teardown-is-bk879b-just-a-rebranded-meter/
 

Offline Seekonk

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Re: Fluke 341A DC voltage calibrator
« Reply #7 on: November 30, 2015, 07:25:12 pm »
I have one of those calibrators and havent turned it on in a while.  When I got it half a dozen plastic spacers of the waffer switches were broken.  That was dicey getting those in without unsoldering anything.
 

Offline EC8010

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Re: Fluke 341A DC voltage calibrator
« Reply #8 on: May 04, 2022, 04:04:16 pm »
I see that your Fluke has a missing (presumed broken) right rack mount handle. Mine had a smashed left hand handle, so I removed them both. Would you like an unbroken handle?
 

Offline feedback.loopTopic starter

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Re: Fluke 341A DC voltage calibrator
« Reply #9 on: May 04, 2022, 04:13:57 pm »
I see that your Fluke has a missing (presumed broken) right rack mount handle. Mine had a smashed left hand handle, so I removed them both. Would you like an unbroken handle?

Apparently you did not watch the video.
My handle is fine, thank you.
 

Offline EC8010

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Re: Fluke 341A DC voltage calibrator
« Reply #10 on: May 05, 2022, 11:26:10 am »
Actually, I did. But I note that you've edited your post to show a new still image. :) I'll keep the undamaged handle just in case.
 


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