About Astigmatism & its Remedies [ Practically ].?

Question

In Oscilloscopes .

Answer 1

Aside from 'tweaking' the collimator elements voltage, there really isn't much you can do to adjust the amount of astigmatism (spot deformation) that the beam goes through from one side of the CRT face to the other. It's virtually all controlled by the geometry of the electron gun assembly and that's inside the tube itself. Running the 2'nd anode voltage a bit to the low side might help some (since the field will be smaller and won't de-focus the beam as much) but the trade-off is that it won't be as bright. The unfortunate truth is that some of the older CRT's were just pretty damned grim.

Doug