Memory tuning is the default mode you’ll probably use it most of the time.
YT Operations Manual Version 1.1 14 Full Tuning Cycle You may need to run a full tuning cycle even when stored parameters are available. For example, you or the elements may have changed some aspect of your antenna, or reoriented it. In that case the stored parameters may not be optimal. Forcing a full tune will cause the YT to seek anew match regardless of what is already stored in memory for the current frequency. To force a full tuning cycle, press and hold the Tune button on the front panel of the YT until the StatusLED lights up, and keep holding until the Status LED goes out again. Release the Tune button once the Status LED goes out. A full tuning cycle will begin. When tuning is complete, the transceiver will be restored to its previous operating mode and power level. You will notice that the radio toggles between VFO A and VFO B before and after a tuning cycle. This is normal.