Gould Oscilloscope OS1200 Sweep compression
 

I have just recently aquired a Gould OS1200 oscilloscope.

Basically it works fine except that the Sweep trace compresses up on
the right hand side of the when I set the timebase to 5uS and up.

I have measured most test points on the Horizontal timebase PCB and
cannot find anything unusual.

Please the following example pictures showing the compresses trace.
Also have photos showing the Sawtooth ramp generator and ramp output
if this helps.

I am really lking for some guidance on where I should be checking.

Regards
Ivan