Uniden X66 Owner's Manual page 22

Operation
RX only Channels (CH22, CH23, CH61, CH62 and
CH63) will not be included in MASTER SCAN Mode
even though stored into GS Memory. Also channels for
which Duplex Setting are On will be skipped in MASTER
NOTE
SCAN Mode.
To select MASTER SCAN Mode:
1. Press [MENU] two times.
2. Press /
OS: Scan mode becomes Open Scan
GS: Scan mode becomes Group Scan
PO: Master Scan is ON with the current GS channel memory.
P1: Master Scan is ON with loading CH09-20 in GS.
P2: Master Scan is ON with loading CH21-30, 39, 40 in GS.
P3: Master Scan is ON with loading CH49-60 in GS.
P4: Master Scan is ON with loading CH61-70, 79, 80 in GS.
UNIDEN X66
to change the setting.
22 UHF CB Transceiver