CADET III VIDEO Input, output level verification

Hi there after the Vector Hack Festival I’m back to complete my LZX Cadet system. I’m kind of blindly aiming at making work the Video Input, Sync Gen, Ramps. Right now I think my Sync Gen works. The Ramps works only in the top part. So I decided to try the Video Input cause it seems an easy build. I tried inputting video from my Mac -> Extron VSC500 (VID out) -> CADET III top input and measuring the output jack (LUMA) with a scope. I see a rough variation of about 1V in the input if I put a black or white video + Brightness increases the signal turning the pot from 12 o clock counter clockwise or clockwise. Of course there is always the sync signal. Is that supposed to work like that? Only weird thing is I have an offset of about 7.5V. This is regardless of what is plugged in. Uploading a picture just in case.

you know you have to patch the video into the sync generator first , right?

video -> sync gen in -> sync gen out -> Cadet III video input in

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Hmm I was trying to avoid The Sync Gen in order to test it independently. I will try as you said. Thanks Martijn.

Ughh, a power cable with two red sides :confused:
Not an issue because of the shrowed (typo) header but always a risk. I learned the hard way sadly :man_facepalming:t2:

post a pic of the backside too

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Thanks!! I hope the quality is not so bad.

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Is that a TL071? Just off the top of my head, there were no TL071’s in any Cadet BOM.

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aw right!!! true I put the wrong IC!!! thanks!

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ok, that could have caused all sorts of wackiness. Let us know what results you get.


Changing the IC worked :)))))