Re: Tektronix 2465A noise on readout


Dave Wise
 

Do I take it that C1813 was open-circuit?
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Gregor via groups.io <gregor_ruf=yahoo.com@groups.io>
Sent: Monday, October 12, 2020 1:52 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tektronix 2465A noise on readout

I fixed it! Now it's working fine.
And of course, I'll tell you how.
After the last test, I was pretty confident that the problem lies in the HV power supply. So I continued searching for the error there. After carefully probing around in the HV supply, I found that the focus voltage (measured on C1813) had a big ripple on it. Here is the image of the voltage on C1813: https://groups.io/g/TekScopes/photo/254966/1
Then I desoldered C1813 and checked it, and I found that it was definitely broken.
Image of desoldered C1813: https://groups.io/g/TekScopes/photo/254966/2
I replaced it as you can see in the following picture: https://groups.io/g/TekScopes/photo/254966/4
And look at the next picture: https://groups.io/g/TekScopes/photo/254966/3

Now it has a perfectly sharp trace and readouts without any noise! I am super happy now :). So finally I can enjoy my 2465A.
Its always a great feeling getting something to work again.
And of course, thanks for all of your suggestions and support! I appreciate it very much :)

-Gregor

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