There's more than one 830 model from Bernina. If yours is the "Record" model from the 70's it's worth putting a little "shop time" in it. The resale is fantastic on these.
There are plenty of maintenance videos out there that cover oiling. The top flips up, the nose cover swings out, the free arm can be exposed, and the drive end and motor covers come off as well as the bottom cover and motor cover. The spool stand and back cover can be removed also, all exposing oiling points. On some of the models the oiling points were highlighted with red paint. Mine isn't painted but the oil points are obvious. The manual does a fair job of describing this.
So... This machine doesn't spin as freely by turning the handwheel as a lot of machines out there. It's the belt drive system that creates some drag. Also there are perceived "tight" spots in the rotation. This is common in oscillating hook models, but when well maintained the difference is sometimes hard to feel.
These really are wonderful sewers, and with the resale being what it is, it's worth putting some money into if you can't do it yourself.