TWR- Tower frequencyGND - Ground frequencyATS - ATIS frequencyATF - Air Traffic FrequencyAPP - ApproachARR - ArrivalAWS - Automatic Weather StationCLR- Clearance/DeliveryCTF- Common Traffic Advisory FrequencyDEP - Departure frequencyFSS - Flight Service StationRFS - Remote Flight Service StationUNI - Unicom frequencyMF - Mandatory FrequencyAuto Stack List (LST)The SL40 keeps track of the last eight Activefrequencies and stores them in a stack. Duplicatefrequencies are not stored.Press RCL and then turn the Large,outer knob to display the Auto StackList (LST).Then, turn the Small, inner knob to viewthe stored frequencies. Frequencies areshown in the order of use.User Stored Frequencies (MEM)When you press the MEM button the Standby frequencyis stored in User memory. The SL40 stores the last eightfrequencies selected by the user. After eight Userfrequencies are stored, you will be prompted that thestack is full (mem full). You may then remove or replacethe frequency, or abort the process. Duplicatefrequencies are not stored.Press RCL and then turn the Large,outer knob to reach the Userfrequencies.Turn the Small, inner knob to view theUser stored frequencies in numericorder.5Basic OperationRCL119.10 LST121.80119.10 MEM121.80RCL119.10 MEM124.55