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Products => Test Equipment => Topic started by: TimFox on June 17, 2016, 08:45:05 pm

Title: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: TimFox on June 17, 2016, 08:45:05 pm
My most recent acquisition is an -hp- 3403C wide-band rms voltmeter.  I received it in operating condition (with one broken panel knob).  The problem is the 3 x 3 matrix of LED indicators to the right of the digital display, for overload, AC-coupling, uprange, etc.  Apparently, someone had cleaned the transparent plastic with a solvent, and all of the labels on the annunciator matrix have disappeared.
The manual is available online at the manufacturer's website, but I could find no drawing or illustration of the physical placement of these indicators.
If someone has a 3403C in good order, could they post the appropriate information as a 3 x 3 table? 
Thanks.
Title: Re: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: retiredcaps on June 17, 2016, 08:56:43 pm
If someone has a 3403C in good order, could they post the appropriate information as a 3 x 3 table? 
I may be misinterpreting your request, but do you mean something like this photo?

https://accusrc.com/uploads/images/img3048.jpg
Title: Re: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: TimFox on June 17, 2016, 09:08:10 pm
Thanks for the quick reply.
Yes, the photo has what I am looking for (the 3 x 3 matrix) except that I can't read the top center and lower right labels in that photograph.
Title: Re: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: retiredcaps on June 17, 2016, 09:18:20 pm
Looking at the service manual,

http://www.keysight.com/upload/cmc_upload/All/3403C_True_RMS_Voltmeter.pdf (http://www.keysight.com/upload/cmc_upload/All/3403C_True_RMS_Voltmeter.pdf)

section 3-28 and 4-55, my guess is that the top center is RNG (range).  You can easily test this by measuring something out of range.

As for the lower right, let me look through the manual some more.
Title: Re: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: retiredcaps on June 17, 2016, 09:30:19 pm
Lower right might be REM for remote.  See section 5-31 of service manual.
Title: Re: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: gusnovak on June 17, 2016, 09:47:31 pm
the letters are in a second layer attached to the LEDs, look if the plate is falling within the voltmeter
Title: Re: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: retiredcaps on June 17, 2016, 09:49:51 pm
Cool, I was right by process of elimination.
Title: Re: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: TimFox on June 17, 2016, 10:19:47 pm
the letters are in a second layer attached to the LEDs, look if the plate is falling within the voltmeter
I'll check for plate tectonics this weekend.  Meanwhile, between these replies, I have the information if I need to make my own label.
Thanks to all.
Title: Re: -hp- 3403C digital true-rms voltmeter: annunciator LEDs
Post by: TimFox on June 21, 2016, 09:58:26 pm
Unfortunately, there is no label plate bouncing around inside the unit.
I shall try making a replacement with laser-print transparency sheet material.