This is what My manual says: (sorry for the poor picture..)
The last time I calibrated my 485 this worked...
On Fri, 23 Apr 2021, 22:51 Ondrej Pavelka, <email@example.com>
Hello to the group,
Is anybody on here familiar closely with 485 calibration? In particular
the Auto Focus section.
There is a time continuum breach making my brain go into feedback loop and
It's point 13) If I simplify it, it says put 3MHz in Channel 1, display
nice 2 divisions high sinewave and adjust focus and astigmatism at low
intensity for sharp trace. That works perfectly.
Next step is to raise intensity to 50V and check if focus bias does
anything, if it does you continue the procedure if it does not you are
advised to skip forward to 13. This is where my brain melts. Because 13 is
definitely skip backwards and it says nothing about how to resolve this
In my case focus bias does nothing with Z out voltage at all nor does it
anything with actual focus.