Hallo, this is my first post,
I would like to build a octopus curve tracer like shown in the attached pdf file, my problem is, I don’t understand why it want be connected to the scope x input and to channe A and B, Channel A and B is clear, I understand why but the x input I be wondering if it
in relation with the trigger circuit of the scope?
Thank you if somebody can explain me some more in detai.

 

Welcome to AAC!

You can't use the built-in horizontal sweep circuitry. If you don't have anything connected to the external horizontal input of the scope, you won't have any horizontal deflection.

 

Thank you for the answer, so it mussed be a misunderstanding from me because I thought the horizontal and vertical deflection was a comparison of the A and B channel of the scope in x-Y mode.

 

it mussed be a misunderstanding from me because I thought the horizontal and vertical deflection was a comparison of the A and B channel of the scope in x-Y mode.

The vertical inputs only provide vertical deflection.

If you have a scope like Tektronix 7404A 7704A that's a mainframe with 4 slots, 2 each for vertical and horizontal plug-ins, you can install a vertical amp in a horizontal slot to provide horizontal deflection. I'm not aware of any other manufacturer who made scopes with that capability.

EDIT: corrected typo in scope model.

 

Wow, I have not seen a scope like that since the late 60s, early 70s when I worked on them. Nice to see one that still glows. I see your question was well answered so nothing to say on that note.

Ron