Re: 7A26 Ch 1 gain low

 

The small ICs all over the 7A26 board are socketed. I would be inclined to suspect gain set components rather than the ICs themselves.

David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Colin Herbert via Groups.Io
Sent: 13 July 2019 12:05
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7A26 Ch 1 gain low

I have purchased a number of the ICs - #155-0078-10 in order to do some swapping. I am still wondering if theses ICs are soldered in or not. Does anyone have experience of them?
TIA, Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Raymond Domp Frank
Sent: 12 July 2019 18:35
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7A26 Ch 1 gain low

On Fri, Jul 12, 2019 at 02:23 PM, Colin Herbert wrote:


However, on looking closer at the problematic 7A26, I think that the problem
is not only with Ch 1, as the Variable gain control on Ch 2 doesn't give as
much gain increase over the calibrated setting as do both channels on my
"good" 7A26. It is about one half of a major division on the "good" 7A26.
... Which is what I suggested earlier: "I think that's not enough, meaning that overall gain for *both* channels isn't enough. Usually, there's at least half a major division headroom".

Raymond

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