All the antenna configuration diagrams in the K3 manual show a COR on the RX ant input. See pages 41 through 44. 73, Don W3FPR On 11/13/2013 5:43 PM, Brian Alsop wrote: > Guys, > > I thought he said RX antenna input. The COR is on the aux ant input. > There is no COR on the RX antenna input (it's not needed, I think.) > > > 73 de Brian/K3KO >