Z-axis modulation in Tektronix 465B

[jordankersten]

Hello everyone, I have a Tektronix 465B with a small issue: There seems to be some Z-axis modulation of some kind. I will attach a pic of the screen. When there is supposed to be a straight trace, you get some chops in the trace. It is most noticeable at slower times. Also, at faster times, there is a slight bending up of the beam on the left side. Any ideas?

 

[jordankersten]

Re: 465B Z-axis?

Here are a few more pictures. With a signal, you can see slight "ghosting" It won't focus in clear. You can also see some noise in the waveform that scans along the wave.