Rotary encoder with no detents.  This replacement data encoder has a D-shaft, and is Nord part number 24010.
If this encoder is not available, you can use part #2101 as a replacement; it is identical, except that is has detents instead of a smooth rotation.
Installation of this part requires soldering.
This item is NEW.
                                    Out of stock.
                                
                                                            
                            
                                                            
                                                        $24.95
(Part #1990)
Click on photo to enlarge

