I've disassembled the VFO mechanism sufficiently that I know the culprit. I just don't know what to call it, as there's no mechanical drawing in the manual, or list of VFO mechanical parts that I can find. The problem is with the shaft, bearings & gear that the VFO knob connects directly to. Everything looks to be brass except for the aluminum shaft.
Once I backed off the knurled (and spring-loaded as i discovered) brass nut that holds it all together a bit, the "catching" stopped. But now when I tighten it even hand-tight (it needed wrenches to remove) it again catches at several points around its rotation. There is some grease inside along with the three bearings, though my disassembly/reassembly may have caused some to be lost.?The knurled nut on my FV-301 is quite tight, so I doubt that tightness is the problem. Perhaps I need to get some more grease back in with the bearings?? If so, any suggestions on specific type? (something hopefully available at Home Depot or a repair shop?)
As a bit more description of the components... The aluminum shaft is inserted into the hollow brass shaft, and has a flared area near the end that captures the bearings, which are inserted thru holes in the side of the brass shaft. It all is held in compression by a spring inside the end of the brass shaft, with another smaller bearing between the spring and the end of the aluminum shaft, and a spring inside the knurled nut.
Joel, VE6EI
Joel Weder, VE6EI