Some digital modes can require careful tuning without drift - also when sending beacons. My shack / office / pigpen is stable between 18C and 22C so I expect that the K3 wouldn't really drift that much. Simon Brown, HB9DRV ----- Original Message ----- From: <Paul at N4LCD.com> > > With the K3, when would someone benefit by having the KTCXO3-1? >