Hey there,
My 54601A scope just came down with a problem today where wave readings come out very distorted (steady voltage readings still look fine). I have a couple pictures to illustrate.
1MHz square wave with series 680-ohm resistor before the problem occurred. -- http://www.facebook.com/photo.php?pid=31139675&l=f1a49d1043&id=47701284
1MHz square wave with series 680-ohm resistor AFTER problem occurred. -- http://www.facebook.com/photo.php?pid=31139677&l=487f7ba0a3&id=47701284
1MHz square wave with series 1.5k-ohm resistor before problem occurred. Screen was squashed which I fixed with a replacement cap according to another thread here (view) -- http://www.facebook.com/photo.php?pid=31139671&l=1e0ccd8e51&id=47701284
1MHz square wave with series 1.5k-ohm resistor AFTER problem occurred. -- http://www.facebook.com/photo.php?pid=31139676&l=8b32e0c3d0&id=47701284
It seems that perhaps the signal is being sampled on top of itself over and over.. can you guys please provide your thoughts on what could be wrong and perhaps how to go about fixing it? I have all the schematics attached on the aforementioned thread and I would really appreciate your insight. Thanks in advance.
-David
My 54601A scope just came down with a problem today where wave readings come out very distorted (steady voltage readings still look fine). I have a couple pictures to illustrate.
1MHz square wave with series 680-ohm resistor before the problem occurred. -- http://www.facebook.com/photo.php?pid=31139675&l=f1a49d1043&id=47701284
1MHz square wave with series 680-ohm resistor AFTER problem occurred. -- http://www.facebook.com/photo.php?pid=31139677&l=487f7ba0a3&id=47701284
1MHz square wave with series 1.5k-ohm resistor before problem occurred. Screen was squashed which I fixed with a replacement cap according to another thread here (view) -- http://www.facebook.com/photo.php?pid=31139671&l=1e0ccd8e51&id=47701284
1MHz square wave with series 1.5k-ohm resistor AFTER problem occurred. -- http://www.facebook.com/photo.php?pid=31139676&l=8b32e0c3d0&id=47701284
It seems that perhaps the signal is being sampled on top of itself over and over.. can you guys please provide your thoughts on what could be wrong and perhaps how to go about fixing it? I have all the schematics attached on the aforementioned thread and I would really appreciate your insight. Thanks in advance.
-David
The picture you showed is typical of unsynchronized sweep caused by incorrect setting or a defective trigger circuit. Didn't you inadvertently engage the HF rejection filter for the trigger coupling? If so, any signal with frequency above 50 kHz, and 1 MHz in particular, will be blocked and so fail to trigger the sweep.