[Test-Equipment] Oszilloscope CTR TO-3

[Alfred Heyden]

Dear gentlemen,
I purchased this scope a few days ago. After switching on, the
trace is sharp and fairly bright.
This keeps a couple of minutes and then the trace disappears
slowly. I have measured around
the crt-tube some voltages when the trace is visuable and
non-visuable. They are not different
regardless of the trace. Adjusting the trace-gain and  vertical
and horizontal position is o.k. Y-input can be
seen on the screen, but with an input-signal the trace cannot
focused very sharp.
The tube is the 75AJB1 manufactured by Matsushito. I don't have a
data-sheet or
pin-layout or anything else about the scope. I need help to get
back this neat box again ready for work.
Any hints and informations for the scope itself are very
appreciated.
BTW, excuse for the English.

Regards, Alfred, nr Bonn/Germany