Hi all,
I recently got hold of an old Tektronix 453 oscilloscope. It seems to work just fine, but the trace seems to be way off-screen horizontally:
When I press the "beam finder" button, which is supposed to compress the display to fit all of a trace, I can see the trace running as a dot that moves about 1/16th of a div at a position of approx 75% of the display's width. I can adjust the horizontal position of that dot by about 1/2 div. When I release the "beam finder" button, I get a horizontal streak to the right and the trace is gone again.
After opening the cover and measuring the horizontal deflection plates' voltage (to ground), one plate constantly read approx. 110V, the other
0V, which seems to be off-scale - I expected something like a sawtooth of approx. 75V on both. When I shorten the plates, the dot is dead-center.Could it be that something is wrong with the horizontal amplifier circuit?
I hope this is a common fault of this series and you can give me blind advice on where and how to check for errors - I wouldn't know where to start...
Thanks in advance,
Wolf