Re: Kenwood Osciloscope
Try demagnetizing the whole scope with something like a large TV de-gausing coil. 8O
This may sound very strange but I have cured many Kenwoods with exactly this problem. Take off the covers and see if there is any improvement on the screen. If it then seems to look better you know you are on the right track. The frame and or covers seem to get magnetized somehow and this upsets the trace causing a wavy, un-even intensity trace.
If you can take a pic of the trace on the screen I may be able to help you more. The CRT's on these scope's were very reliable.
E