Tektronix 434 s/n below 500000 faulty ps.

[johnmcgivern]

If I turn the Timebase cal knob fully clockwise or anti clockwise nothing happens to the waveform. The pot does nothing.

Which Timebase cal knob is this?

Craig I am really sorry for asking all these questions I have watched many oscilloscope videos and tutorials but its like learning to drive you can read and listen but nothing beats practicle experience and making mistakes which I am trying my best to avoid with this scope due to rarity of parts.
See photo's when timebase set to 0.1m/S should each gradient have a signal?