Author Topic: Symmetry issue with function gen EZ/Goldstar FG-8002  (Read 716 times)

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Offline rodcastler

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Symmetry issue with function gen EZ/Goldstar FG-8002
« on: February 26, 2018, 12:21:45 pm »
Hi,

My FG-8002 analog function gen (AKA GoldStar FG-8002) has a symmetry function that has the desired effect on symmetry however the knob also adjusts frequency, undesirably and quite substantially.

I would expect for the knob to adjust duty cycle, while keeping the previously set frequency steady.

I wonder if this is a design failure of this model or something broken that I should be able to fix.


« Last Edit: March 07, 2018, 10:36:18 pm by rodcastler »
 

Offline rodcastler

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Re: Symmetry issue with function gen EZ/Goldstar FG-8002
« Reply #1 on: March 01, 2018, 03:47:41 am »
I found the attached schematic for this unit.

I suspect that something fishy could be going on with U5 or U4, where the two (freq and symmetry) appear to mix.

Any thoughts on where should I begin? and most importantly, do anybody else experience the same issue with this unit? Like I said, I'm not sure if it is working per design...
« Last Edit: March 14, 2018, 12:16:36 pm by rodcastler »
 


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